diff --git a/alias.c b/alias.c
index 54a1a23d2c..910dd252a0 100644
--- a/alias.c
+++ b/alias.c
@@ -12,7 +12,8 @@ struct config_alias_data {
 	struct string_list *list;
 };
 
-static int config_alias_cb(const char *key, const char *value, void *d)
+static int config_alias_cb(const char *key, const char *value,
+			   const struct config_context *ctx UNUSED, void *d)
 {
 	struct config_alias_data *data = d;
 	const char *p;
diff --git a/archive-tar.c b/archive-tar.c
index 4cd81d8161..ef06e516b1 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -411,7 +411,8 @@ static int tar_filter_config(const char *var, const char *value,
 	return 0;
 }
 
-static int git_tar_config(const char *var, const char *value, void *cb)
+static int git_tar_config(const char *var, const char *value,
+			  const struct config_context *ctx UNUSED, void *cb)
 {
 	if (!strcmp(var, "tar.umask")) {
 		if (value && !strcmp(value, "user")) {
diff --git a/archive-zip.c b/archive-zip.c
index d0d065a312..b681195195 100644
--- a/archive-zip.c
+++ b/archive-zip.c
@@ -617,6 +617,7 @@ static void dos_time(timestamp_t *timestamp, int *dos_date, int *dos_time)
 }
 
 static int archive_zip_config(const char *var, const char *value,
+			      const struct config_context *ctx UNUSED,
 			      void *data UNUSED)
 {
 	return userdiff_config(var, value);
diff --git a/builtin/add.c b/builtin/add.c
index e01efdfc50..1009ae13c1 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -357,7 +357,8 @@ static struct option builtin_add_options[] = {
 	OPT_END(),
 };
 
-static int add_config(const char *var, const char *value, void *cb)
+static int add_config(const char *var, const char *value,
+		      const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "add.ignoreerrors") ||
 	    !strcmp(var, "add.ignore-errors")) {
@@ -368,7 +369,7 @@ static int add_config(const char *var, const char *value, void *cb)
 	if (git_color_config(var, value, cb) < 0)
 		return -1;
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static const char embedded_advice[] = N_(
diff --git a/builtin/blame.c b/builtin/blame.c
index 2df6039a6e..d0970a1ab1 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -694,7 +694,8 @@ static const char *add_prefix(const char *prefix, const char *path)
 	return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
 }
 
-static int git_blame_config(const char *var, const char *value, void *cb)
+static int git_blame_config(const char *var, const char *value,
+			    const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "blame.showroot")) {
 		show_root = git_config_bool(var, value);
@@ -767,7 +768,7 @@ static int git_blame_config(const char *var, const char *value, void *cb)
 	if (userdiff_config(var, value) < 0)
 		return -1;
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static int blame_copy_callback(const struct option *option, const char *arg, int unset)
diff --git a/builtin/branch.c b/builtin/branch.c
index 8337b9e71b..af6d2e75fb 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -83,7 +83,8 @@ static unsigned int colopts;
 
 define_list_config_array(color_branch_slots);
 
-static int git_branch_config(const char *var, const char *value, void *cb)
+static int git_branch_config(const char *var, const char *value,
+			     const struct config_context *ctx, void *cb)
 {
 	const char *slot_name;
 
@@ -120,7 +121,7 @@ static int git_branch_config(const char *var, const char *value, void *cb)
 	if (git_color_config(var, value, cb) < 0)
 		return -1;
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static const char *branch_get_color(enum color_branch ix)
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 7ff56d5a78..b3c41b54c8 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -873,12 +873,13 @@ static int batch_objects(struct batch_options *opt)
 	return retval;
 }
 
-static int git_cat_file_config(const char *var, const char *value, void *cb)
+static int git_cat_file_config(const char *var, const char *value,
+			       const struct config_context *ctx, void *cb)
 {
 	if (userdiff_config(var, value) < 0)
 		return -1;
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static int batch_option_callback(const struct option *opt,
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 715eeb5048..4e1f7dc26c 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1186,7 +1186,8 @@ static int switch_branches(const struct checkout_opts *opts,
 	return ret || writeout_error;
 }
 
-static int git_checkout_config(const char *var, const char *value, void *cb)
+static int git_checkout_config(const char *var, const char *value,
+			       const struct config_context *ctx, void *cb)
 {
 	struct checkout_opts *opts = cb;
 
@@ -1202,7 +1203,7 @@ static int git_checkout_config(const char *var, const char *value, void *cb)
 	if (starts_with(var, "submodule."))
 		return git_default_submodule_config(var, value, NULL);
 
-	return git_xmerge_config(var, value, NULL);
+	return git_xmerge_config(var, value, ctx, NULL);
 }
 
 static void setup_new_branch_info_and_source_tree(
@@ -1689,8 +1690,13 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 	}
 
 	if (opts->conflict_style) {
+		struct key_value_info kvi = KVI_INIT;
+		struct config_context ctx = {
+			.kvi = &kvi,
+		};
 		opts->merge = 1; /* implied */
-		git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL);
+		git_xmerge_config("merge.conflictstyle", opts->conflict_style,
+				  &ctx, NULL);
 	}
 	if (opts->force) {
 		opts->discard_changes = 1;
diff --git a/builtin/clean.c b/builtin/clean.c
index 57e7f7cac6..5eff1b802a 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -103,7 +103,8 @@ struct menu_stuff {
 
 define_list_config_array(color_interactive_slots);
 
-static int git_clean_config(const char *var, const char *value, void *cb)
+static int git_clean_config(const char *var, const char *value,
+			    const struct config_context *ctx, void *cb)
 {
 	const char *slot_name;
 
@@ -133,7 +134,7 @@ static int git_clean_config(const char *var, const char *value, void *cb)
 	if (git_color_config(var, value, cb) < 0)
 		return -1;
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static const char *clean_get_color(enum color_clean ix)
diff --git a/builtin/clone.c b/builtin/clone.c
index 15f9912b4c..c0f6e06749 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -790,7 +790,8 @@ static int checkout(int submodule_progress, int filter_submodules)
 	return err;
 }
 
-static int git_clone_config(const char *k, const char *v, void *cb)
+static int git_clone_config(const char *k, const char *v,
+			    const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(k, "clone.defaultremotename")) {
 		free(remote_name);
@@ -801,17 +802,19 @@ static int git_clone_config(const char *k, const char *v, void *cb)
 	if (!strcmp(k, "clone.filtersubmodules"))
 		config_filter_submodules = git_config_bool(k, v);
 
-	return git_default_config(k, v, cb);
+	return git_default_config(k, v, ctx, cb);
 }
 
-static int write_one_config(const char *key, const char *value, void *data)
+static int write_one_config(const char *key, const char *value,
+			    const struct config_context *ctx,
+			    void *data)
 {
 	/*
 	 * give git_clone_config a chance to write config values back to the
 	 * environment, since git_config_set_multivar_gently only deals with
 	 * config-file writes
 	 */
-	int apply_failed = git_clone_config(key, value, data);
+	int apply_failed = git_clone_config(key, value, ctx, data);
 	if (apply_failed)
 		return apply_failed;
 
diff --git a/builtin/column.c b/builtin/column.c
index de623a16c2..4a6148ca47 100644
--- a/builtin/column.c
+++ b/builtin/column.c
@@ -13,7 +13,8 @@ static const char * const builtin_column_usage[] = {
 };
 static unsigned int colopts;
 
-static int column_config(const char *var, const char *value, void *cb)
+static int column_config(const char *var, const char *value,
+			 const struct config_context *ctx UNUSED, void *cb)
 {
 	return git_column_config(var, value, cb, &colopts);
 }
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index dd732b3534..1185c49239 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -186,6 +186,7 @@ static int write_option_max_new_filters(const struct option *opt,
 }
 
 static int git_commit_graph_write_config(const char *var, const char *value,
+					 const struct config_context *ctx UNUSED,
 					 void *cb UNUSED)
 {
 	if (!strcmp(var, "commitgraph.maxnewfilters"))
diff --git a/builtin/commit.c b/builtin/commit.c
index 9ab57ea1aa..6a2b250332 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1405,7 +1405,8 @@ static int parse_status_slot(const char *slot)
 	return LOOKUP_CONFIG(color_status_slots, slot);
 }
 
-static int git_status_config(const char *k, const char *v, void *cb)
+static int git_status_config(const char *k, const char *v,
+			     const struct config_context *ctx, void *cb)
 {
 	struct wt_status *s = cb;
 	const char *slot_name;
@@ -1490,7 +1491,7 @@ static int git_status_config(const char *k, const char *v, void *cb)
 		s->detect_rename = git_config_rename(k, v);
 		return 0;
 	}
-	return git_diff_ui_config(k, v, NULL);
+	return git_diff_ui_config(k, v, ctx, NULL);
 }
 
 int cmd_status(int argc, const char **argv, const char *prefix)
@@ -1605,7 +1606,8 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
-static int git_commit_config(const char *k, const char *v, void *cb)
+static int git_commit_config(const char *k, const char *v,
+			     const struct config_context *ctx, void *cb)
 {
 	struct wt_status *s = cb;
 
@@ -1627,7 +1629,7 @@ static int git_commit_config(const char *k, const char *v, void *cb)
 		return 0;
 	}
 
-	return git_status_config(k, v, s);
+	return git_status_config(k, v, ctx, s);
 }
 
 int cmd_commit(int argc, const char **argv, const char *prefix)
diff --git a/builtin/config.c b/builtin/config.c
index d40fddb042..f4fccf99cb 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -217,6 +217,7 @@ static void show_config_scope(struct strbuf *buf)
 }
 
 static int show_all_config(const char *key_, const char *value_,
+			   const struct config_context *ctx UNUSED,
 			   void *cb UNUSED)
 {
 	if (show_origin || show_scope) {
@@ -301,7 +302,8 @@ static int format_config(struct strbuf *buf, const char *key_, const char *value
 	return 0;
 }
 
-static int collect_config(const char *key_, const char *value_, void *cb)
+static int collect_config(const char *key_, const char *value_,
+			  const struct config_context *ctx UNUSED, void *cb)
 {
 	struct strbuf_list *values = cb;
 
@@ -470,6 +472,7 @@ static const char *get_colorbool_slot;
 static char parsed_color[COLOR_MAXLEN];
 
 static int git_get_color_config(const char *var, const char *value,
+				const struct config_context *ctx UNUSED,
 				void *cb UNUSED)
 {
 	if (!strcmp(var, get_color_slot)) {
@@ -503,6 +506,7 @@ static int get_colorbool_found;
 static int get_diff_color_found;
 static int get_color_ui_found;
 static int git_get_colorbool_config(const char *var, const char *value,
+				    const struct config_context *ctx UNUSED,
 				    void *data UNUSED)
 {
 	if (!strcmp(var, get_colorbool_slot))
@@ -561,7 +565,9 @@ struct urlmatch_current_candidate_value {
 	struct strbuf value;
 };
 
-static int urlmatch_collect_fn(const char *var, const char *value, void *cb)
+static int urlmatch_collect_fn(const char *var, const char *value,
+			       const struct config_context *ctx UNUSED,
+			       void *cb)
 {
 	struct string_list *values = cb;
 	struct string_list_item *item = string_list_insert(values, var);
diff --git a/builtin/difftool.c b/builtin/difftool.c
index 0049342f5c..f289530068 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -40,14 +40,15 @@ static const char *const builtin_difftool_usage[] = {
 	NULL
 };
 
-static int difftool_config(const char *var, const char *value, void *cb)
+static int difftool_config(const char *var, const char *value,
+			   const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "difftool.trustexitcode")) {
 		trust_exit_code = git_config_bool(var, value);
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static int print_tool_help(void)
diff --git a/builtin/fetch.c b/builtin/fetch.c
index e3871048cf..a4aa0fbb8f 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -110,7 +110,8 @@ struct fetch_config {
 	int submodule_fetch_jobs;
 };
 
-static int git_fetch_config(const char *k, const char *v, void *cb)
+static int git_fetch_config(const char *k, const char *v,
+			    const struct config_context *ctx, void *cb)
 {
 	struct fetch_config *fetch_config = cb;
 
@@ -164,7 +165,7 @@ static int git_fetch_config(const char *k, const char *v, void *cb)
 			    "fetch.output", v);
 	}
 
-	return git_default_config(k, v, cb);
+	return git_default_config(k, v, ctx, cb);
 }
 
 static int parse_refmap_arg(const struct option *opt, const char *arg, int unset)
@@ -1799,7 +1800,9 @@ struct remote_group_data {
 	struct string_list *list;
 };
 
-static int get_remote_group(const char *key, const char *value, void *priv)
+static int get_remote_group(const char *key, const char *value,
+			    const struct config_context *ctx UNUSED,
+			    void *priv)
 {
 	struct remote_group_data *g = priv;
 
diff --git a/builtin/fsmonitor--daemon.c b/builtin/fsmonitor--daemon.c
index f6dd9a784c..91a776e2f1 100644
--- a/builtin/fsmonitor--daemon.c
+++ b/builtin/fsmonitor--daemon.c
@@ -37,7 +37,8 @@ static int fsmonitor__start_timeout_sec = 60;
 #define FSMONITOR__ANNOUNCE_STARTUP "fsmonitor.announcestartup"
 static int fsmonitor__announce_startup = 0;
 
-static int fsmonitor_config(const char *var, const char *value, void *cb)
+static int fsmonitor_config(const char *var, const char *value,
+			    const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, FSMONITOR__IPC_THREADS)) {
 		int i = git_config_int(var, value);
@@ -67,7 +68,7 @@ static int fsmonitor_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 /*
diff --git a/builtin/grep.c b/builtin/grep.c
index 76cf999d31..757d52b94e 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -290,13 +290,14 @@ static int wait_all(void)
 	return hit;
 }
 
-static int grep_cmd_config(const char *var, const char *value, void *cb)
+static int grep_cmd_config(const char *var, const char *value,
+			   const struct config_context *ctx, void *cb)
 {
-	int st = grep_config(var, value, cb);
+	int st = grep_config(var, value, ctx, cb);
 
 	if (git_color_config(var, value, cb) < 0)
 		st = -1;
-	else if (git_default_config(var, value, cb) < 0)
+	else if (git_default_config(var, value, ctx, cb) < 0)
 		st = -1;
 
 	if (!strcmp(var, "grep.threads")) {
diff --git a/builtin/help.c b/builtin/help.c
index d3cf4af3f6..c348f20125 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -398,7 +398,8 @@ static int add_man_viewer_info(const char *var, const char *value)
 	return 0;
 }
 
-static int git_help_config(const char *var, const char *value, void *cb)
+static int git_help_config(const char *var, const char *value,
+			   const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "help.format")) {
 		if (!value)
@@ -421,7 +422,7 @@ static int git_help_config(const char *var, const char *value, void *cb)
 	if (starts_with(var, "man."))
 		return add_man_viewer_info(var, value);
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static struct cmdnames main_cmds, other_cmds;
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index d0d8067510..de8884ea5c 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1581,7 +1581,8 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 	strbuf_release(&pack_name);
 }
 
-static int git_index_pack_config(const char *k, const char *v, void *cb)
+static int git_index_pack_config(const char *k, const char *v,
+				 const struct config_context *ctx, void *cb)
 {
 	struct pack_idx_option *opts = cb;
 
@@ -1608,7 +1609,7 @@ static int git_index_pack_config(const char *k, const char *v, void *cb)
 		else
 			opts->flags &= ~WRITE_REV;
 	}
-	return git_default_config(k, v, cb);
+	return git_default_config(k, v, ctx, cb);
 }
 
 static int cmp_uint32(const void *a_, const void *b_)
diff --git a/builtin/log.c b/builtin/log.c
index c85f13a5d5..09d6a13075 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -564,7 +564,8 @@ static int cmd_log_walk(struct rev_info *rev)
 	return retval;
 }
 
-static int git_log_config(const char *var, const char *value, void *cb)
+static int git_log_config(const char *var, const char *value,
+			  const struct config_context *ctx, void *cb)
 {
 	const char *slot_name;
 
@@ -613,7 +614,7 @@ static int git_log_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return git_diff_ui_config(var, value, cb);
+	return git_diff_ui_config(var, value, ctx, cb);
 }
 
 int cmd_whatchanged(int argc, const char **argv, const char *prefix)
@@ -979,7 +980,8 @@ static enum cover_from_description parse_cover_from_description(const char *arg)
 		die(_("%s: invalid cover from description mode"), arg);
 }
 
-static int git_format_config(const char *var, const char *value, void *cb)
+static int git_format_config(const char *var, const char *value,
+			     const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "format.headers")) {
 		if (!value)
@@ -1108,7 +1110,7 @@ static int git_format_config(const char *var, const char *value, void *cb)
 	if (!strcmp(var, "diff.noprefix"))
 		return 0;
 
-	return git_log_config(var, value, cb);
+	return git_log_config(var, value, ctx, cb);
 }
 
 static const char *output_directory = NULL;
diff --git a/builtin/merge.c b/builtin/merge.c
index 8da3e46abb..cad624fb79 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -623,7 +623,8 @@ static void parse_branch_merge_options(char *bmo)
 	free(argv);
 }
 
-static int git_merge_config(const char *k, const char *v, void *cb)
+static int git_merge_config(const char *k, const char *v,
+			    const struct config_context *ctx, void *cb)
 {
 	int status;
 	const char *str;
@@ -668,10 +669,10 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 		return 0;
 	}
 
-	status = fmt_merge_msg_config(k, v, cb);
+	status = fmt_merge_msg_config(k, v, ctx, cb);
 	if (status)
 		return status;
-	return git_diff_ui_config(k, v, cb);
+	return git_diff_ui_config(k, v, ctx, cb);
 }
 
 static int read_tree_trivial(struct object_id *common, struct object_id *head,
diff --git a/builtin/multi-pack-index.c b/builtin/multi-pack-index.c
index 1b5083f8b2..a0a7b82cc6 100644
--- a/builtin/multi-pack-index.c
+++ b/builtin/multi-pack-index.c
@@ -82,6 +82,7 @@ static struct option *add_common_options(struct option *prev)
 }
 
 static int git_multi_pack_index_write_config(const char *var, const char *value,
+					     const struct config_context *ctx UNUSED,
 					     void *cb UNUSED)
 {
 	if (!strcmp(var, "pack.writebitmaphashcache")) {
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 3af2d84f58..34aa0b483a 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -3135,7 +3135,8 @@ static void prepare_pack(int window, int depth)
 	free(delta_list);
 }
 
-static int git_pack_config(const char *k, const char *v, void *cb)
+static int git_pack_config(const char *k, const char *v,
+			   const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(k, "pack.window")) {
 		window = git_config_int(k, v);
@@ -3227,7 +3228,7 @@ static int git_pack_config(const char *k, const char *v, void *cb)
 		ex->uri = xstrdup(pack_end + 1);
 		oidmap_put(&configured_exclusions, ex);
 	}
-	return git_default_config(k, v, cb);
+	return git_default_config(k, v, ctx, cb);
 }
 
 /* Counters for trace2 output when in --stdin-packs mode. */
diff --git a/builtin/patch-id.c b/builtin/patch-id.c
index 9d5585d3a7..03eddd0fb8 100644
--- a/builtin/patch-id.c
+++ b/builtin/patch-id.c
@@ -196,7 +196,8 @@ struct patch_id_opts {
 	int verbatim;
 };
 
-static int git_patch_id_config(const char *var, const char *value, void *cb)
+static int git_patch_id_config(const char *var, const char *value,
+			       const struct config_context *ctx, void *cb)
 {
 	struct patch_id_opts *opts = cb;
 
@@ -209,7 +210,7 @@ static int git_patch_id_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 int cmd_patch_id(int argc, const char **argv, const char *prefix)
diff --git a/builtin/pull.c b/builtin/pull.c
index 0c7bac97b7..83fca5b1d4 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -361,7 +361,8 @@ static enum rebase_type config_get_rebase(int *rebase_unspecified)
 /**
  * Read config variables.
  */
-static int git_pull_config(const char *var, const char *value, void *cb)
+static int git_pull_config(const char *var, const char *value,
+			   const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "rebase.autostash")) {
 		config_autostash = git_config_bool(var, value);
@@ -374,7 +375,7 @@ static int git_pull_config(const char *var, const char *value, void *cb)
 		check_trust_level = 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 /**
diff --git a/builtin/push.c b/builtin/push.c
index dbdf609daf..a2f68f7732 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -510,7 +510,8 @@ static void set_push_cert_flags(int *flags, int v)
 }
 
 
-static int git_push_config(const char *k, const char *v, void *cb)
+static int git_push_config(const char *k, const char *v,
+			   const struct config_context *ctx, void *cb)
 {
 	const char *slot_name;
 	int *flags = cb;
@@ -577,7 +578,7 @@ static int git_push_config(const char *k, const char *v, void *cb)
 		return 0;
 	}
 
-	return git_default_config(k, v, NULL);
+	return git_default_config(k, v, ctx, NULL);
 }
 
 int cmd_push(int argc, const char **argv, const char *prefix)
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 440f19b1b8..8877dd6d4b 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -102,12 +102,13 @@ static int debug_merge(const struct cache_entry * const *stages,
 	return 0;
 }
 
-static int git_read_tree_config(const char *var, const char *value, void *cb)
+static int git_read_tree_config(const char *var, const char *value,
+				const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "submodule.recurse"))
 		return git_default_submodule_config(var, value, cb);
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
diff --git a/builtin/rebase.c b/builtin/rebase.c
index ace1d5e8d1..60930e2d8e 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -772,7 +772,8 @@ static void parse_rebase_merges_value(struct rebase_options *options, const char
 		die(_("Unknown rebase-merges mode: %s"), value);
 }
 
-static int rebase_config(const char *var, const char *value, void *data)
+static int rebase_config(const char *var, const char *value,
+			 const struct config_context *ctx, void *data)
 {
 	struct rebase_options *opts = data;
 
@@ -831,7 +832,7 @@ static int rebase_config(const char *var, const char *value, void *data)
 		return git_config_string(&opts->default_backend, var, value);
 	}
 
-	return git_default_config(var, value, data);
+	return git_default_config(var, value, ctx, data);
 }
 
 static int checkout_up_to_date(struct rebase_options *options)
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 1a31a58367..94d9898aff 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -139,7 +139,8 @@ static enum deny_action parse_deny_action(const char *var, const char *value)
 	return DENY_IGNORE;
 }
 
-static int receive_pack_config(const char *var, const char *value, void *cb)
+static int receive_pack_config(const char *var, const char *value,
+			       const struct config_context *ctx, void *cb)
 {
 	int status = parse_hide_refs_config(var, value, "receive", &hidden_refs);
 
@@ -266,7 +267,7 @@ static int receive_pack_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static void show_ref(const char *path, const struct object_id *oid)
diff --git a/builtin/reflog.c b/builtin/reflog.c
index a1fa0c855f..84251cc951 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -108,7 +108,8 @@ static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
 #define EXPIRE_TOTAL   01
 #define EXPIRE_UNREACH 02
 
-static int reflog_expire_config(const char *var, const char *value, void *cb)
+static int reflog_expire_config(const char *var, const char *value,
+				const struct config_context *ctx, void *cb)
 {
 	const char *pattern, *key;
 	size_t pattern_len;
@@ -117,7 +118,7 @@ static int reflog_expire_config(const char *var, const char *value, void *cb)
 	struct reflog_expire_cfg *ent;
 
 	if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
-		return git_default_config(var, value, cb);
+		return git_default_config(var, value, ctx, cb);
 
 	if (!strcmp(key, "reflogexpire")) {
 		slot = EXPIRE_TOTAL;
@@ -128,7 +129,7 @@ static int reflog_expire_config(const char *var, const char *value, void *cb)
 		if (git_config_expiry_date(&expire, var, value))
 			return -1;
 	} else
-		return git_default_config(var, value, cb);
+		return git_default_config(var, value, ctx, cb);
 
 	if (!pattern) {
 		switch (slot) {
diff --git a/builtin/remote.c b/builtin/remote.c
index 1e0b137d97..87de81105e 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -268,6 +268,7 @@ static const char *abbrev_ref(const char *name, const char *prefix)
 #define abbrev_branch(name) abbrev_ref((name), "refs/heads/")
 
 static int config_read_branches(const char *key, const char *value,
+				const struct config_context *ctx UNUSED,
 				void *data UNUSED)
 {
 	const char *orig_key = key;
@@ -645,7 +646,7 @@ struct push_default_info
 };
 
 static int config_read_push_default(const char *key, const char *value,
-	void *cb)
+	const struct config_context *ctx UNUSED, void *cb)
 {
 	struct push_default_info* info = cb;
 	if (strcmp(key, "remote.pushdefault") ||
@@ -1494,7 +1495,9 @@ static int prune(int argc, const char **argv, const char *prefix)
 	return result;
 }
 
-static int get_remote_default(const char *key, const char *value UNUSED, void *priv)
+static int get_remote_default(const char *key, const char *value UNUSED,
+			      const struct config_context *ctx UNUSED,
+			      void *priv)
 {
 	if (strcmp(key, "remotes.default") == 0) {
 		int *found = priv;
diff --git a/builtin/repack.c b/builtin/repack.c
index 0541c3ce15..6f74570bf9 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -59,7 +59,8 @@ struct pack_objects_args {
 	int local;
 };
 
-static int repack_config(const char *var, const char *value, void *cb)
+static int repack_config(const char *var, const char *value,
+			 const struct config_context *ctx, void *cb)
 {
 	struct pack_objects_args *cruft_po_args = cb;
 	if (!strcmp(var, "repack.usedeltabaseoffset")) {
@@ -91,7 +92,7 @@ static int repack_config(const char *var, const char *value, void *cb)
 		return git_config_string(&cruft_po_args->depth, var, value);
 	if (!strcmp(var, "repack.cruftthreads"))
 		return git_config_string(&cruft_po_args->threads, var, value);
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 /*
diff --git a/builtin/reset.c b/builtin/reset.c
index f99f32d580..1ae82f2e89 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -312,12 +312,13 @@ static int reset_refs(const char *rev, const struct object_id *oid)
 	return update_ref_status;
 }
 
-static int git_reset_config(const char *var, const char *value, void *cb)
+static int git_reset_config(const char *var, const char *value,
+			    const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "submodule.recurse"))
 		return git_default_submodule_config(var, value, cb);
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 int cmd_reset(int argc, const char **argv, const char *prefix)
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index 4784143004..cd6d9e4112 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -131,7 +131,8 @@ static void print_helper_status(struct ref *ref)
 	strbuf_release(&buf);
 }
 
-static int send_pack_config(const char *k, const char *v, void *cb)
+static int send_pack_config(const char *k, const char *v,
+			    const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(k, "push.gpgsign")) {
 		const char *value;
@@ -151,7 +152,7 @@ static int send_pack_config(const char *k, const char *v, void *cb)
 			}
 		}
 	}
-	return git_default_config(k, v, cb);
+	return git_default_config(k, v, ctx, cb);
 }
 
 int cmd_send_pack(int argc, const char **argv, const char *prefix)
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index a2461270d4..f2fd245b83 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -559,7 +559,8 @@ static void append_one_rev(const char *av)
 	die("bad sha1 reference %s", av);
 }
 
-static int git_show_branch_config(const char *var, const char *value, void *cb)
+static int git_show_branch_config(const char *var, const char *value,
+				  const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "showbranch.default")) {
 		if (!value)
@@ -582,7 +583,7 @@ static int git_show_branch_config(const char *var, const char *value, void *cb)
 	if (git_color_config(var, value, cb) < 0)
 		return -1;
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
diff --git a/builtin/stash.c b/builtin/stash.c
index a7e17ffe38..e5c4246d2d 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -837,7 +837,8 @@ static int show_stat = 1;
 static int show_patch;
 static int show_include_untracked;
 
-static int git_stash_config(const char *var, const char *value, void *cb)
+static int git_stash_config(const char *var, const char *value,
+			    const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "stash.showstat")) {
 		show_stat = git_config_bool(var, value);
@@ -851,7 +852,7 @@ static int git_stash_config(const char *var, const char *value, void *cb)
 		show_include_untracked = git_config_bool(var, value);
 		return 0;
 	}
-	return git_diff_basic_config(var, value, cb);
+	return git_diff_basic_config(var, value, ctx, cb);
 }
 
 static void diff_include_untracked(const struct stash_info *info, struct diff_options *diff_opt)
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6a16208e8a..f8e9d85e77 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -2192,6 +2192,7 @@ static int update_clone_task_finished(int result,
 }
 
 static int git_update_clone_config(const char *var, const char *value,
+				   const struct config_context *ctx UNUSED,
 				   void *cb)
 {
 	int *max_jobs = cb;
diff --git a/builtin/tag.c b/builtin/tag.c
index 1acf5f7a59..b7dfb5e2ca 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -188,7 +188,8 @@ static const char tag_template_nocleanup[] =
 	"Lines starting with '%c' will be kept; you may remove them"
 	" yourself if you want to.\n");
 
-static int git_tag_config(const char *var, const char *value, void *cb)
+static int git_tag_config(const char *var, const char *value,
+			  const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "tag.gpgsign")) {
 		config_sign_tag = git_config_bool(var, value);
@@ -213,7 +214,7 @@ static int git_tag_config(const char *var, const char *value, void *cb)
 	if (git_color_config(var, value, cb) < 0)
 		return -1;
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static void write_tag_body(int fd, const struct object_id *oid)
diff --git a/builtin/var.c b/builtin/var.c
index 2149998980..ae011bdf40 100644
--- a/builtin/var.c
+++ b/builtin/var.c
@@ -71,13 +71,14 @@ static const struct git_var *get_git_var(const char *var)
 	return NULL;
 }
 
-static int show_config(const char *var, const char *value, void *cb)
+static int show_config(const char *var, const char *value,
+		       const struct config_context *ctx, void *cb)
 {
 	if (value)
 		printf("%s=%s\n", var, value);
 	else
 		printf("%s\n", var);
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 int cmd_var(int argc, const char **argv, const char *prefix UNUSED)
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 5a9cf076ad..a30d37a273 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -128,14 +128,15 @@ static int verbose;
 static int guess_remote;
 static timestamp_t expire;
 
-static int git_worktree_config(const char *var, const char *value, void *cb)
+static int git_worktree_config(const char *var, const char *value,
+			       const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "worktree.guessremote")) {
 		guess_remote = git_config_bool(var, value);
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static int delete_git_dir(const char *id)
diff --git a/bundle-uri.c b/bundle-uri.c
index 2a2db1a1d3..0d5acc3dc5 100644
--- a/bundle-uri.c
+++ b/bundle-uri.c
@@ -224,7 +224,9 @@ static int bundle_list_update(const char *key, const char *value,
 	return 0;
 }
 
-static int config_to_bundle_list(const char *key, const char *value, void *data)
+static int config_to_bundle_list(const char *key, const char *value,
+				 const struct config_context *ctx UNUSED,
+				 void *data)
 {
 	struct bundle_list *list = data;
 	return bundle_list_update(key, value, list);
@@ -871,7 +873,9 @@ int bundle_uri_advertise(struct repository *r, struct strbuf *value UNUSED)
 	return advertise_bundle_uri;
 }
 
-static int config_to_packet_line(const char *key, const char *value, void *data)
+static int config_to_packet_line(const char *key, const char *value,
+				 const struct config_context *ctx UNUSED,
+				 void *data)
 {
 	struct packet_reader *writer = data;
 
diff --git a/compat/mingw.c b/compat/mingw.c
index d06cdc6254..4186bc7a41 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -244,7 +244,8 @@ static int core_restrict_inherited_handles = -1;
 static enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 static char *unset_environment_variables;
 
-int mingw_core_config(const char *var, const char *value, void *cb)
+int mingw_core_config(const char *var, const char *value,
+		      const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "core.hidedotfiles")) {
 		if (value && !strcasecmp(value, "dotgitonly"))
diff --git a/compat/mingw.h b/compat/mingw.h
index 209cf7ceba..5e34c87347 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -11,7 +11,9 @@ typedef _sigset_t sigset_t;
 #undef _POSIX_THREAD_SAFE_FUNCTIONS
 #endif
 
-int mingw_core_config(const char *var, const char *value, void *cb);
+struct config_context;
+int mingw_core_config(const char *var, const char *value,
+		      const struct config_context *ctx, void *cb);
 #define platform_core_config mingw_core_config
 
 /*
diff --git a/config.c b/config.c
index 2eeb662142..850e432e30 100644
--- a/config.c
+++ b/config.c
@@ -209,7 +209,8 @@ struct config_include_data {
 };
 #define CONFIG_INCLUDE_INIT { 0 }
 
-static int git_config_include(const char *var, const char *value, void *data);
+static int git_config_include(const char *var, const char *value,
+			      const struct config_context *ctx, void *data);
 
 #define MAX_INCLUDE_DEPTH 10
 static const char include_depth_advice[] = N_(
@@ -388,7 +389,8 @@ static int include_by_branch(const char *cond, size_t cond_len)
 	return ret;
 }
 
-static int add_remote_url(const char *var, const char *value, void *data)
+static int add_remote_url(const char *var, const char *value,
+			  const struct config_context *ctx UNUSED, void *data)
 {
 	struct string_list *remote_urls = data;
 	const char *remote_name;
@@ -423,6 +425,7 @@ static void populate_remote_urls(struct config_include_data *inc)
 }
 
 static int forbid_remote_url(const char *var, const char *value UNUSED,
+			     const struct config_context *ctx UNUSED,
 			     void *data UNUSED)
 {
 	const char *remote_name;
@@ -486,7 +489,9 @@ static int include_condition_is_true(struct config_source *cs,
 	return 0;
 }
 
-static int git_config_include(const char *var, const char *value, void *data)
+static int git_config_include(const char *var, const char *value,
+			      const struct config_context *ctx,
+			      void *data)
 {
 	struct config_include_data *inc = data;
 	struct config_source *cs = inc->config_reader->source;
@@ -498,7 +503,7 @@ static int git_config_include(const char *var, const char *value, void *data)
 	 * Pass along all values, including "include" directives; this makes it
 	 * possible to query information on the includes themselves.
 	 */
-	ret = inc->fn(var, value, inc->data);
+	ret = inc->fn(var, value, NULL, inc->data);
 	if (ret < 0)
 		return ret;
 
@@ -680,7 +685,7 @@ static int config_parse_pair(const char *key, const char *value,
 	if (git_config_parse_key(key, &canonical_name, NULL))
 		return -1;
 
-	ret = (fn(canonical_name, value, data) < 0) ? -1 : 0;
+	ret = (fn(canonical_name, value, NULL, data) < 0) ? -1 : 0;
 	free(canonical_name);
 	return ret;
 }
@@ -968,7 +973,7 @@ static int get_value(struct config_source *cs, config_fn_t fn, void *data,
 	 * accurate line number in error messages.
 	 */
 	cs->linenr--;
-	ret = fn(name->buf, value, data);
+	ret = fn(name->buf, value, NULL, data);
 	if (ret >= 0)
 		cs->linenr++;
 	return ret;
@@ -1562,7 +1567,8 @@ int git_config_color(char *dest, const char *var, const char *value)
 	return 0;
 }
 
-static int git_default_core_config(const char *var, const char *value, void *cb)
+static int git_default_core_config(const char *var, const char *value,
+				   const struct config_context *ctx, void *cb)
 {
 	/* This needs a better name */
 	if (!strcmp(var, "core.filemode")) {
@@ -1842,7 +1848,7 @@ static int git_default_core_config(const char *var, const char *value, void *cb)
 	}
 
 	/* Add other config variables here and to Documentation/config.txt. */
-	return platform_core_config(var, value, cb);
+	return platform_core_config(var, value, ctx, cb);
 }
 
 static int git_default_sparse_config(const char *var, const char *value)
@@ -1944,15 +1950,16 @@ static int git_default_mailmap_config(const char *var, const char *value)
 	return 0;
 }
 
-int git_default_config(const char *var, const char *value, void *cb)
+int git_default_config(const char *var, const char *value,
+		       const struct config_context *ctx, void *cb)
 {
 	if (starts_with(var, "core."))
-		return git_default_core_config(var, value, cb);
+		return git_default_core_config(var, value, ctx, cb);
 
 	if (starts_with(var, "user.") ||
 	    starts_with(var, "author.") ||
 	    starts_with(var, "committer."))
-		return git_ident_config(var, value, cb);
+		return git_ident_config(var, value, ctx, cb);
 
 	if (starts_with(var, "i18n."))
 		return git_default_i18n_config(var, value);
@@ -2318,7 +2325,7 @@ static void configset_iter(struct config_reader *reader, struct config_set *set,
 
 		config_reader_set_kvi(reader, values->items[value_index].util);
 
-		if (fn(entry->key, values->items[value_index].string, data) < 0)
+		if (fn(entry->key, values->items[value_index].string, NULL, data) < 0)
 			git_die_config_linenr(entry->key,
 					      reader->config_kvi->filename,
 					      reader->config_kvi->linenr);
@@ -2496,7 +2503,9 @@ struct configset_add_data {
 };
 #define CONFIGSET_ADD_INIT { 0 }
 
-static int config_set_callback(const char *key, const char *value, void *cb)
+static int config_set_callback(const char *key, const char *value,
+			       const struct config_context *ctx UNUSED,
+			       void *cb)
 {
 	struct configset_add_data *data = cb;
 	configset_add_value(data->config_reader, data->config_set, key, value);
@@ -3106,7 +3115,8 @@ static int store_aux_event(enum config_event_t type,
 	return 0;
 }
 
-static int store_aux(const char *key, const char *value, void *cb)
+static int store_aux(const char *key, const char *value,
+		     const struct config_context *ctx UNUSED, void *cb)
 {
 	struct config_store_data *store = cb;
 
diff --git a/config.h b/config.h
index d1c5577589..cd30125a8a 100644
--- a/config.h
+++ b/config.h
@@ -110,8 +110,29 @@ struct config_options {
 	} error_action;
 };
 
+/* Config source metadata for a given config key-value pair */
+struct key_value_info {
+	const char *filename;
+	int linenr;
+	enum config_origin_type origin_type;
+	enum config_scope scope;
+};
+#define KVI_INIT { \
+	.filename = NULL, \
+	.linenr = -1, \
+	.origin_type = CONFIG_ORIGIN_UNKNOWN, \
+	.scope = CONFIG_SCOPE_UNKNOWN, \
+}
+
+/* Captures additional information that a config callback can use. */
+struct config_context {
+	/* Config source metadata for key and value. */
+	const struct key_value_info *kvi;
+};
+#define CONFIG_CONTEXT_INIT { 0 }
+
 /**
- * A config callback function takes three parameters:
+ * A config callback function takes four parameters:
  *
  * - the name of the parsed variable. This is in canonical "flat" form: the
  *   section, subsection, and variable segments will be separated by dots,
@@ -122,15 +143,22 @@ struct config_options {
  *   value specified, the value will be NULL (typically this means it
  *   should be interpreted as boolean true).
  *
+ * - the 'config context', that is, additional information about the config
+ *   iteration operation provided by the config machinery. For example, this
+ *   includes information about the config source being parsed (e.g. the
+ *   filename).
+ *
  * - a void pointer passed in by the caller of the config API; this can
  *   contain callback-specific data
  *
  * A config callback should return 0 for success, or -1 if the variable
  * could not be parsed properly.
  */
-typedef int (*config_fn_t)(const char *, const char *, void *);
+typedef int (*config_fn_t)(const char *, const char *,
+			   const struct config_context *, void *);
 
-int git_default_config(const char *, const char *, void *);
+int git_default_config(const char *, const char *,
+		       const struct config_context *, void *);
 
 /**
  * Read a specific file in git-config format.
@@ -667,13 +695,6 @@ int git_config_get_expiry(const char *key, const char **output);
 /* parse either "this many days" integer, or "5.days.ago" approxidate */
 int git_config_get_expiry_in_days(const char *key, timestamp_t *, timestamp_t now);
 
-struct key_value_info {
-	const char *filename;
-	int linenr;
-	enum config_origin_type origin_type;
-	enum config_scope scope;
-};
-
 /**
  * First prints the error message specified by the caller in `err` and then
  * dies printing the line number and the file name of the highest priority
diff --git a/connect.c b/connect.c
index 3a0186280c..cddac1d96b 100644
--- a/connect.c
+++ b/connect.c
@@ -964,7 +964,7 @@ static struct child_process *git_tcp_connect(int fd[2], char *host, int flags)
 static char *git_proxy_command;
 
 static int git_proxy_command_options(const char *var, const char *value,
-		void *cb)
+		const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "core.gitproxy")) {
 		const char *for_pos;
@@ -1010,7 +1010,7 @@ static int git_proxy_command_options(const char *var, const char *value,
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static int git_use_proxy(const char *host)
diff --git a/contrib/coccinelle/config_fn_ctx.pending.cocci b/contrib/coccinelle/config_fn_ctx.pending.cocci
new file mode 100644
index 0000000000..6d3d1000a9
--- /dev/null
+++ b/contrib/coccinelle/config_fn_ctx.pending.cocci
@@ -0,0 +1,144 @@
+@ get_fn @
+identifier fn, R;
+@@
+(
+(
+git_config_from_file
+|
+git_config_from_file_with_options
+|
+git_config_from_mem
+|
+git_config_from_blob_oid
+|
+read_early_config
+|
+read_very_early_config
+|
+config_with_options
+|
+git_config
+|
+git_protected_config
+|
+config_from_gitmodules
+)
+  (fn, ...)
+|
+repo_config(R, fn, ...)
+)
+
+@ extends get_fn @
+identifier C1, C2, D;
+@@
+int fn(const char *C1, const char *C2,
++ const struct config_context *ctx,
+  void *D);
+
+@ extends get_fn @
+@@
+int fn(const char *, const char *,
++ const struct config_context *,
+  void *);
+
+@ extends get_fn @
+// Don't change fns that look like callback fns but aren't
+identifier fn2 != tar_filter_config && != git_diff_heuristic_config &&
+  != git_default_submodule_config && != git_color_config &&
+  != bundle_list_update && != parse_object_filter_config;
+identifier C1, C2, D1, D2, S;
+attribute name UNUSED;
+@@
+int fn(const char *C1, const char *C2,
++ const struct config_context *ctx,
+  void *D1) {
+<+...
+(
+fn2(C1, C2
++ , ctx
+, D2);
+|
+if(fn2(C1, C2
++ , ctx
+, D2) < 0) { ... }
+|
+return fn2(C1, C2
++ , ctx
+, D2);
+|
+S = fn2(C1, C2
++ , ctx
+, D2);
+)
+...+>
+  }
+
+@ extends get_fn@
+identifier C1, C2, D;
+attribute name UNUSED;
+@@
+int fn(const char *C1, const char *C2,
++ const struct config_context *ctx UNUSED,
+  void *D) {...}
+
+
+// The previous rules don't catch all callbacks, especially if they're defined
+// in a separate file from the git_config() call. Fix these manually.
+@@
+identifier C1, C2, D;
+attribute name UNUSED;
+@@
+int
+(
+git_ident_config
+|
+urlmatch_collect_fn
+|
+write_one_config
+|
+forbid_remote_url
+|
+credential_config_callback
+)
+  (const char *C1, const char *C2,
++ const struct config_context *ctx UNUSED,
+  void *D) {...}
+
+@@
+identifier C1, C2, D, D2, S, fn2;
+@@
+int
+(
+http_options
+|
+git_status_config
+|
+git_commit_config
+|
+git_default_core_config
+|
+grep_config
+)
+  (const char *C1, const char *C2,
++ const struct config_context *ctx,
+  void *D) {
+<+...
+(
+fn2(C1, C2
++ , ctx
+, D2);
+|
+if(fn2(C1, C2
++ , ctx
+, D2) < 0) { ... }
+|
+return fn2(C1, C2
++ , ctx
+, D2);
+|
+S = fn2(C1, C2
++ , ctx
+, D2);
+)
+...+>
+  }
diff --git a/convert.c b/convert.c
index 9ee79fe469..8e96cf8303 100644
--- a/convert.c
+++ b/convert.c
@@ -1015,7 +1015,9 @@ static int apply_filter(const char *path, const char *src, size_t len,
 	return 0;
 }
 
-static int read_convert_config(const char *var, const char *value, void *cb UNUSED)
+static int read_convert_config(const char *var, const char *value,
+			       const struct config_context *ctx UNUSED,
+			       void *cb UNUSED)
 {
 	const char *key, *name;
 	size_t namelen;
diff --git a/credential.c b/credential.c
index 8825c6f132..d664754163 100644
--- a/credential.c
+++ b/credential.c
@@ -49,6 +49,7 @@ static int credential_from_potentially_partial_url(struct credential *c,
 						   const char *url);
 
 static int credential_config_callback(const char *var, const char *value,
+				      const struct config_context *ctx UNUSED,
 				      void *data)
 {
 	struct credential *c = data;
diff --git a/delta-islands.c b/delta-islands.c
index c824a5f6a4..5fc6ea6ff5 100644
--- a/delta-islands.c
+++ b/delta-islands.c
@@ -341,7 +341,9 @@ static void free_remote_islands(kh_str_t *remote_islands)
 	kh_destroy_str(remote_islands);
 }
 
-static int island_config_callback(const char *k, const char *v, void *cb)
+static int island_config_callback(const char *k, const char *v,
+				  const struct config_context *ctx UNUSED,
+				  void *cb)
 {
 	struct island_load_data *ild = cb;
 
diff --git a/diff.c b/diff.c
index c106f8a4ff..0e382c8f7f 100644
--- a/diff.c
+++ b/diff.c
@@ -357,7 +357,8 @@ static unsigned parse_color_moved_ws(const char *arg)
 	return ret;
 }
 
-int git_diff_ui_config(const char *var, const char *value, void *cb)
+int git_diff_ui_config(const char *var, const char *value,
+		       const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 		diff_use_color_default = git_config_colorbool(var, value);
@@ -440,10 +441,11 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 	if (git_color_config(var, value, cb) < 0)
 		return -1;
 
-	return git_diff_basic_config(var, value, cb);
+	return git_diff_basic_config(var, value, ctx, cb);
 }
 
-int git_diff_basic_config(const char *var, const char *value, void *cb)
+int git_diff_basic_config(const char *var, const char *value,
+			  const struct config_context *ctx, void *cb)
 {
 	const char *name;
 
@@ -495,7 +497,7 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
 	if (git_diff_heuristic_config(var, value, cb) < 0)
 		return -1;
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static char *quote_two(const char *one, const char *two)
diff --git a/diff.h b/diff.h
index 6c10ce289d..33a4f4d598 100644
--- a/diff.h
+++ b/diff.h
@@ -531,10 +531,13 @@ void free_diffstat_info(struct diffstat_t *diffstat);
 int parse_long_opt(const char *opt, const char **argv,
 		   const char **optarg);
 
-int git_diff_basic_config(const char *var, const char *value, void *cb);
+struct config_context;
+int git_diff_basic_config(const char *var, const char *value,
+			  const struct config_context *ctx, void *cb);
 int git_diff_heuristic_config(const char *var, const char *value, void *cb);
 void init_diff_ui_defaults(void);
-int git_diff_ui_config(const char *var, const char *value, void *cb);
+int git_diff_ui_config(const char *var, const char *value,
+		       const struct config_context *ctx, void *cb);
 void repo_diff_setup(struct repository *, struct diff_options *);
 struct option *add_diff_options(const struct option *, struct diff_options *);
 int diff_opt_parse(struct diff_options *, const char **, int, const char *);
diff --git a/fetch-pack.c b/fetch-pack.c
index 0f71054fba..5f3d40f3d0 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1860,7 +1860,8 @@ static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
 	return ref;
 }
 
-static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
+static int fetch_pack_config_cb(const char *var, const char *value,
+				const struct config_context *ctx, void *cb)
 {
 	if (strcmp(var, "fetch.fsck.skiplist") == 0) {
 		const char *path;
@@ -1882,7 +1883,7 @@ static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static void fetch_pack_config(void)
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
index 5af0d4715b..1013744432 100644
--- a/fmt-merge-msg.c
+++ b/fmt-merge-msg.c
@@ -20,7 +20,8 @@ static int use_branch_desc;
 static int suppress_dest_pattern_seen;
 static struct string_list suppress_dest_patterns = STRING_LIST_INIT_DUP;
 
-int fmt_merge_msg_config(const char *key, const char *value, void *cb)
+int fmt_merge_msg_config(const char *key, const char *value,
+			 const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
 		int is_bool;
@@ -40,7 +41,7 @@ int fmt_merge_msg_config(const char *key, const char *value, void *cb)
 			string_list_append(&suppress_dest_patterns, value);
 		suppress_dest_pattern_seen = 1;
 	} else {
-		return git_default_config(key, value, cb);
+		return git_default_config(key, value, ctx, cb);
 	}
 	return 0;
 }
diff --git a/fmt-merge-msg.h b/fmt-merge-msg.h
index 99054042dc..73ca3e4465 100644
--- a/fmt-merge-msg.h
+++ b/fmt-merge-msg.h
@@ -13,7 +13,8 @@ struct fmt_merge_msg_opts {
 };
 
 extern int merge_log_config;
-int fmt_merge_msg_config(const char *key, const char *value, void *cb);
+int fmt_merge_msg_config(const char *key, const char *value,
+			 const struct config_context *ctx, void *cb);
 int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 		  struct fmt_merge_msg_opts *);
 
diff --git a/fsck.c b/fsck.c
index 3261ef9ec2..55b6a69485 100644
--- a/fsck.c
+++ b/fsck.c
@@ -1163,7 +1163,9 @@ struct fsck_gitmodules_data {
 	int ret;
 };
 
-static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
+static int fsck_gitmodules_fn(const char *var, const char *value,
+			      const struct config_context *ctx UNUSED,
+			      void *vdata)
 {
 	struct fsck_gitmodules_data *data = vdata;
 	const char *subsection, *key;
@@ -1373,7 +1375,8 @@ int fsck_finish(struct fsck_options *options)
 	return ret;
 }
 
-int git_fsck_config(const char *var, const char *value, void *cb)
+int git_fsck_config(const char *var, const char *value,
+		    const struct config_context *ctx, void *cb)
 {
 	struct fsck_options *options = cb;
 	if (strcmp(var, "fsck.skiplist") == 0) {
@@ -1394,7 +1397,7 @@ int git_fsck_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 /*
diff --git a/fsck.h b/fsck.h
index e17730e9da..6359ba359b 100644
--- a/fsck.h
+++ b/fsck.h
@@ -233,10 +233,12 @@ void fsck_put_object_name(struct fsck_options *options,
 const char *fsck_describe_object(struct fsck_options *options,
 				 const struct object_id *oid);
 
+struct key_value_info;
 /*
  * git_config() callback for use by fsck-y tools that want to support
  * fsck.<msg> fsck.skipList etc.
  */
-int git_fsck_config(const char *var, const char *value, void *cb);
+int git_fsck_config(const char *var, const char *value,
+		    const struct config_context *ctx, void *cb);
 
 #endif
diff --git a/git-compat-util.h b/git-compat-util.h
index 5b2b99c17c..14e8aacb95 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -440,8 +440,10 @@ typedef uintmax_t timestamp_t;
 #endif
 
 #ifndef platform_core_config
+struct config_context;
 static inline int noop_core_config(const char *var UNUSED,
 				   const char *value UNUSED,
+				   const struct config_context *ctx UNUSED,
 				   void *cb UNUSED)
 {
 	return 0;
diff --git a/gpg-interface.c b/gpg-interface.c
index 19a3471a0b..57c862a3a2 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -14,7 +14,8 @@
 #include "alias.h"
 #include "wrapper.h"
 
-static int git_gpg_config(const char *, const char *, void *);
+static int git_gpg_config(const char *, const char *,
+			  const struct config_context *, void *);
 
 static void gpg_interface_lazy_init(void)
 {
@@ -720,7 +721,9 @@ void set_signing_key(const char *key)
 	configured_signing_key = xstrdup(key);
 }
 
-static int git_gpg_config(const char *var, const char *value, void *cb UNUSED)
+static int git_gpg_config(const char *var, const char *value,
+			  const struct config_context *ctx UNUSED,
+			  void *cb UNUSED)
 {
 	struct gpg_format *fmt = NULL;
 	char *fmtname = NULL;
diff --git a/grep.c b/grep.c
index f00986c451..fc22c3e2af 100644
--- a/grep.c
+++ b/grep.c
@@ -56,7 +56,8 @@ define_list_config_array_extra(color_grep_slots, {"match"});
  * Read the configuration file once and store it in
  * the grep_defaults template.
  */
-int grep_config(const char *var, const char *value, void *cb)
+int grep_config(const char *var, const char *value,
+		const struct config_context *ctx, void *cb)
 {
 	struct grep_opt *opt = cb;
 	const char *slot;
@@ -91,9 +92,9 @@ int grep_config(const char *var, const char *value, void *cb)
 	if (!strcmp(var, "color.grep"))
 		opt->color = git_config_colorbool(var, value);
 	if (!strcmp(var, "color.grep.match")) {
-		if (grep_config("color.grep.matchcontext", value, cb) < 0)
+		if (grep_config("color.grep.matchcontext", value, ctx, cb) < 0)
 			return -1;
-		if (grep_config("color.grep.matchselected", value, cb) < 0)
+		if (grep_config("color.grep.matchselected", value, ctx, cb) < 0)
 			return -1;
 	} else if (skip_prefix(var, "color.grep.", &slot)) {
 		int i = LOOKUP_CONFIG(color_grep_slots, slot);
diff --git a/grep.h b/grep.h
index c59592e3bd..926c0875c4 100644
--- a/grep.h
+++ b/grep.h
@@ -202,7 +202,9 @@ struct grep_opt {
 	.output = std_output, \
 }
 
-int grep_config(const char *var, const char *value, void *);
+struct config_context;
+int grep_config(const char *var, const char *value,
+		const struct config_context *ctx, void *data);
 void grep_init(struct grep_opt *, struct repository *repo);
 
 void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen, const char *origin, int no, enum grep_pat_token t);
diff --git a/help.c b/help.c
index 5d7637dce9..ac0ae5ac0d 100644
--- a/help.c
+++ b/help.c
@@ -309,7 +309,8 @@ void load_command_list(const char *prefix,
 	exclude_cmds(other_cmds, main_cmds);
 }
 
-static int get_colopts(const char *var, const char *value, void *data)
+static int get_colopts(const char *var, const char *value,
+		       const struct config_context *ctx UNUSED, void *data)
 {
 	unsigned int *colopts = data;
 
@@ -459,7 +460,8 @@ void list_developer_interfaces_help(void)
 	putchar('\n');
 }
 
-static int get_alias(const char *var, const char *value, void *data)
+static int get_alias(const char *var, const char *value,
+		     const struct config_context *ctx UNUSED, void *data)
 {
 	struct string_list *list = data;
 
@@ -543,6 +545,7 @@ static struct cmdnames aliases;
 #define AUTOCORRECT_IMMEDIATELY (-1)
 
 static int git_unknown_cmd_config(const char *var, const char *value,
+				  const struct config_context *ctx UNUSED,
 				  void *cb UNUSED)
 {
 	const char *p;
diff --git a/http.c b/http.c
index bb58bb3e6a..762502828c 100644
--- a/http.c
+++ b/http.c
@@ -363,7 +363,8 @@ static void process_curl_messages(void)
 	}
 }
 
-static int http_options(const char *var, const char *value, void *cb)
+static int http_options(const char *var, const char *value,
+			const struct config_context *ctx, void *data)
 {
 	if (!strcmp("http.version", var)) {
 		return git_config_string(&curl_http_version, var, value);
@@ -534,7 +535,7 @@ static int http_options(const char *var, const char *value, void *cb)
 	}
 
 	/* Fall back on the default ones */
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, data);
 }
 
 static int curl_empty_auth_enabled(void)
diff --git a/ident.c b/ident.c
index 8fad92d700..08be4d0747 100644
--- a/ident.c
+++ b/ident.c
@@ -671,7 +671,9 @@ static int set_ident(const char *var, const char *value)
 	return 0;
 }
 
-int git_ident_config(const char *var, const char *value, void *data UNUSED)
+int git_ident_config(const char *var, const char *value,
+		     const struct config_context *ctx UNUSED,
+		     void *data UNUSED)
 {
 	if (!strcmp(var, "user.useconfigonly")) {
 		ident_use_config_only = git_config_bool(var, value);
diff --git a/ident.h b/ident.h
index 96a64896a0..6a79febba1 100644
--- a/ident.h
+++ b/ident.h
@@ -62,6 +62,8 @@ const char *fmt_name(enum want_ident);
 int committer_ident_sufficiently_given(void);
 int author_ident_sufficiently_given(void);
 
-int git_ident_config(const char *, const char *, void *);
+struct config_context;
+int git_ident_config(const char *, const char *, const struct config_context *,
+		     void *);
 
 #endif
diff --git a/imap-send.c b/imap-send.c
index 7f5426177a..47777e7686 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -1323,7 +1323,8 @@ static int split_msg(struct strbuf *all_msgs, struct strbuf *msg, int *ofs)
 	return 1;
 }
 
-static int git_imap_config(const char *var, const char *val, void *cb)
+static int git_imap_config(const char *var, const char *val,
+			   const struct config_context *ctx, void *cb)
 {
 
 	if (!strcmp("imap.sslverify", var))
@@ -1357,7 +1358,7 @@ static int git_imap_config(const char *var, const char *val, void *cb)
 			server.host = xstrdup(val);
 		}
 	} else
-		return git_default_config(var, val, cb);
+		return git_default_config(var, val, ctx, cb);
 
 	return 0;
 }
diff --git a/ll-merge.c b/ll-merge.c
index 07ec16e8e5..3936d112e0 100644
--- a/ll-merge.c
+++ b/ll-merge.c
@@ -254,6 +254,7 @@ static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
 static const char *default_ll_merge;
 
 static int read_merge_config(const char *var, const char *value,
+			     const struct config_context *ctx UNUSED,
 			     void *cb UNUSED)
 {
 	struct ll_merge_driver *fn;
diff --git a/ls-refs.c b/ls-refs.c
index f385938b64..a29c2364a5 100644
--- a/ls-refs.c
+++ b/ls-refs.c
@@ -137,6 +137,7 @@ static void send_possibly_unborn_head(struct ls_refs_data *data)
 }
 
 static int ls_refs_config(const char *var, const char *value,
+			  const struct config_context *ctx UNUSED,
 			  void *cb_data)
 {
 	struct ls_refs_data *data = cb_data;
diff --git a/mailinfo.c b/mailinfo.c
index 2aeb20e5e6..931505363c 100644
--- a/mailinfo.c
+++ b/mailinfo.c
@@ -1241,12 +1241,13 @@ int mailinfo_parse_quoted_cr_action(const char *actionstr, int *action)
 	return 0;
 }
 
-static int git_mailinfo_config(const char *var, const char *value, void *mi_)
+static int git_mailinfo_config(const char *var, const char *value,
+			       const struct config_context *ctx, void *mi_)
 {
 	struct mailinfo *mi = mi_;
 
 	if (!starts_with(var, "mailinfo."))
-		return git_default_config(var, value, NULL);
+		return git_default_config(var, value, ctx, NULL);
 	if (!strcmp(var, "mailinfo.scissors")) {
 		mi->use_scissors = git_config_bool(var, value);
 		return 0;
diff --git a/notes-utils.c b/notes-utils.c
index 4a793eb347..97c031c26e 100644
--- a/notes-utils.c
+++ b/notes-utils.c
@@ -94,7 +94,9 @@ static combine_notes_fn parse_combine_notes_fn(const char *v)
 		return NULL;
 }
 
-static int notes_rewrite_config(const char *k, const char *v, void *cb)
+static int notes_rewrite_config(const char *k, const char *v,
+				const struct config_context *ctx UNUSED,
+				void *cb)
 {
 	struct notes_rewrite_cfg *c = cb;
 	if (starts_with(k, "notes.rewrite.") && !strcmp(k+14, c->cmd)) {
diff --git a/notes.c b/notes.c
index f51a2d3630..e68645a4b8 100644
--- a/notes.c
+++ b/notes.c
@@ -974,7 +974,9 @@ void string_list_add_refs_from_colon_sep(struct string_list *list,
 	free(globs_copy);
 }
 
-static int notes_display_config(const char *k, const char *v, void *cb)
+static int notes_display_config(const char *k, const char *v,
+				const struct config_context *ctx UNUSED,
+				void *cb)
 {
 	int *load_refs = cb;
 
diff --git a/pager.c b/pager.c
index 63055d0873..b8822a9381 100644
--- a/pager.c
+++ b/pager.c
@@ -43,6 +43,7 @@ static void wait_for_pager_signal(int signo)
 }
 
 static int core_pager_config(const char *var, const char *value,
+			     const struct config_context *ctx UNUSED,
 			     void *data UNUSED)
 {
 	if (!strcmp(var, "core.pager"))
@@ -228,7 +229,9 @@ struct pager_command_config_data {
 	char *value;
 };
 
-static int pager_command_config(const char *var, const char *value, void *vdata)
+static int pager_command_config(const char *var, const char *value,
+				const struct config_context *ctx UNUSED,
+				void *vdata)
 {
 	struct pager_command_config_data *data = vdata;
 	const char *cmd;
diff --git a/pretty.c b/pretty.c
index 0bb938021b..8724535345 100644
--- a/pretty.c
+++ b/pretty.c
@@ -56,6 +56,7 @@ static void save_user_format(struct rev_info *rev, const char *cp, int is_tforma
 }
 
 static int git_pretty_formats_config(const char *var, const char *value,
+				     const struct config_context *ctx UNUSED,
 				     void *cb UNUSED)
 {
 	struct cmt_fmt_map *commit_format = NULL;
diff --git a/promisor-remote.c b/promisor-remote.c
index 1adcd6fb0a..c22abb85b1 100644
--- a/promisor-remote.c
+++ b/promisor-remote.c
@@ -100,7 +100,9 @@ static void promisor_remote_move_to_tail(struct promisor_remote_config *config,
 	config->promisors_tail = &r->next;
 }
 
-static int promisor_remote_config(const char *var, const char *value, void *data)
+static int promisor_remote_config(const char *var, const char *value,
+				  const struct config_context *ctx UNUSED,
+				  void *data)
 {
 	struct promisor_remote_config *config = data;
 	const char *name;
diff --git a/remote.c b/remote.c
index 1bcd36e358..241999c284 100644
--- a/remote.c
+++ b/remote.c
@@ -349,7 +349,8 @@ static void read_branches_file(struct remote_state *remote_state,
 	remote->fetch_tags = 1; /* always auto-follow */
 }
 
-static int handle_config(const char *key, const char *value, void *cb)
+static int handle_config(const char *key, const char *value,
+			 const struct config_context *ctx UNUSED, void *cb)
 {
 	const char *name;
 	size_t namelen;
diff --git a/revision.c b/revision.c
index b33cc1d106..87ed8ccd44 100644
--- a/revision.c
+++ b/revision.c
@@ -1572,7 +1572,9 @@ struct exclude_hidden_refs_cb {
 	const char *section;
 };
 
-static int hide_refs_config(const char *var, const char *value, void *cb_data)
+static int hide_refs_config(const char *var, const char *value,
+			    const struct config_context *ctx UNUSED,
+			    void *cb_data)
 {
 	struct exclude_hidden_refs_cb *cb = cb_data;
 	cb->exclusions->hidden_refs_configured = 1;
diff --git a/scalar.c b/scalar.c
index 1326e1f608..df7358f481 100644
--- a/scalar.c
+++ b/scalar.c
@@ -594,7 +594,9 @@ static int cmd_register(int argc, const char **argv)
 	return register_dir();
 }
 
-static int get_scalar_repos(const char *key, const char *value, void *data)
+static int get_scalar_repos(const char *key, const char *value,
+			    const struct config_context *ctx UNUSED,
+			    void *data)
 {
 	struct string_list *list = data;
 
diff --git a/sequencer.c b/sequencer.c
index bceb6abcb6..34754d1759 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -219,7 +219,8 @@ static struct update_ref_record *init_update_ref_record(const char *ref)
 	return rec;
 }
 
-static int git_sequencer_config(const char *k, const char *v, void *cb)
+static int git_sequencer_config(const char *k, const char *v,
+				const struct config_context *ctx, void *cb)
 {
 	struct replay_opts *opts = cb;
 	int status;
@@ -274,7 +275,7 @@ static int git_sequencer_config(const char *k, const char *v, void *cb)
 	if (opts->action == REPLAY_REVERT && !strcmp(k, "revert.reference"))
 		opts->commit_use_reference = git_config_bool(k, v);
 
-	return git_diff_basic_config(k, v, NULL);
+	return git_diff_basic_config(k, v, ctx, NULL);
 }
 
 void sequencer_init_config(struct replay_opts *opts)
@@ -2881,7 +2882,9 @@ static int git_config_string_dup(char **dest,
 	return 0;
 }
 
-static int populate_opts_cb(const char *key, const char *value, void *data)
+static int populate_opts_cb(const char *key, const char *value,
+			    const struct config_context *ctx UNUSED,
+			    void *data)
 {
 	struct replay_opts *opts = data;
 	int error_flag = 1;
diff --git a/setup.c b/setup.c
index 6f6e92b96b..fadba5bab4 100644
--- a/setup.c
+++ b/setup.c
@@ -517,7 +517,9 @@ static void setup_original_cwd(void)
 	startup_info->original_cwd = NULL;
 }
 
-static int read_worktree_config(const char *var, const char *value, void *vdata)
+static int read_worktree_config(const char *var, const char *value,
+				const struct config_context *ctx UNUSED,
+				void *vdata)
 {
 	struct repository_format *data = vdata;
 
@@ -588,7 +590,8 @@ static enum extension_result handle_extension(const char *var,
 	return EXTENSION_UNKNOWN;
 }
 
-static int check_repo_format(const char *var, const char *value, void *vdata)
+static int check_repo_format(const char *var, const char *value,
+			     const struct config_context *ctx, void *vdata)
 {
 	struct repository_format *data = vdata;
 	const char *ext;
@@ -617,7 +620,7 @@ static int check_repo_format(const char *var, const char *value, void *vdata)
 		}
 	}
 
-	return read_worktree_config(var, value, vdata);
+	return read_worktree_config(var, value, ctx, vdata);
 }
 
 static int check_repository_format_gently(const char *gitdir, struct repository_format *candidate, int *nongit_ok)
@@ -1115,7 +1118,8 @@ struct safe_directory_data {
 	int is_safe;
 };
 
-static int safe_directory_cb(const char *key, const char *value, void *d)
+static int safe_directory_cb(const char *key, const char *value,
+			     const struct config_context *ctx UNUSED, void *d)
 {
 	struct safe_directory_data *data = d;
 
@@ -1171,7 +1175,9 @@ static int ensure_valid_ownership(const char *gitfile,
 	return data.is_safe;
 }
 
-static int allowed_bare_repo_cb(const char *key, const char *value, void *d)
+static int allowed_bare_repo_cb(const char *key, const char *value,
+				const struct config_context *ctx UNUSED,
+				void *d)
 {
 	enum allowed_bare_repo *allowed_bare_repo = d;
 
diff --git a/submodule-config.c b/submodule-config.c
index 7eb7a0d88d..a38d4d4973 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -426,7 +426,8 @@ struct parse_config_parameter {
  * config store (.git/config, etc).  Callers are responsible for
  * checking for overrides in the main config store when appropriate.
  */
-static int parse_config(const char *var, const char *value, void *data)
+static int parse_config(const char *var, const char *value,
+			const struct config_context *ctx UNUSED, void *data)
 {
 	struct parse_config_parameter *me = data;
 	struct submodule *submodule;
@@ -674,7 +675,8 @@ static void config_from_gitmodules(config_fn_t fn, struct repository *repo, void
 	}
 }
 
-static int gitmodules_cb(const char *var, const char *value, void *data)
+static int gitmodules_cb(const char *var, const char *value,
+			 const struct config_context *ctx, void *data)
 {
 	struct repository *repo = data;
 	struct parse_config_parameter parameter;
@@ -684,7 +686,7 @@ static int gitmodules_cb(const char *var, const char *value, void *data)
 	parameter.gitmodules_oid = null_oid();
 	parameter.overwrite = 1;
 
-	return parse_config(var, value, &parameter);
+	return parse_config(var, value, ctx, &parameter);
 }
 
 void repo_read_gitmodules(struct repository *repo, int skip_if_read)
@@ -801,7 +803,9 @@ void submodule_free(struct repository *r)
 		submodule_cache_clear(r->submodule_cache);
 }
 
-static int config_print_callback(const char *var, const char *value, void *cb_data)
+static int config_print_callback(const char *var, const char *value,
+				 const struct config_context *ctx UNUSED,
+				 void *cb_data)
 {
 	char *wanted_key = cb_data;
 
@@ -843,7 +847,9 @@ struct fetch_config {
 	int *recurse_submodules;
 };
 
-static int gitmodules_fetch_config(const char *var, const char *value, void *cb)
+static int gitmodules_fetch_config(const char *var, const char *value,
+				   const struct config_context *ctx UNUSED,
+				   void *cb)
 {
 	struct fetch_config *config = cb;
 	if (!strcmp(var, "submodule.fetchjobs")) {
@@ -871,6 +877,7 @@ void fetch_config_from_gitmodules(int *max_children, int *recurse_submodules)
 }
 
 static int gitmodules_update_clone_config(const char *var, const char *value,
+					  const struct config_context *ctx UNUSED,
 					  void *cb)
 {
 	int *max_jobs = cb;
diff --git a/t/helper/test-config.c b/t/helper/test-config.c
index ad78fc1768..85ad815358 100644
--- a/t/helper/test-config.c
+++ b/t/helper/test-config.c
@@ -42,7 +42,9 @@
  *
  */
 
-static int iterate_cb(const char *var, const char *value, void *data UNUSED)
+static int iterate_cb(const char *var, const char *value,
+		      const struct config_context *ctx UNUSED,
+		      void *data UNUSED)
 {
 	static int nr;
 
@@ -59,7 +61,8 @@ static int iterate_cb(const char *var, const char *value, void *data UNUSED)
 	return 0;
 }
 
-static int parse_int_cb(const char *var, const char *value, void *data)
+static int parse_int_cb(const char *var, const char *value,
+			const struct config_context *ctx UNUSED, void *data)
 {
 	const char *key_to_match = data;
 
@@ -70,7 +73,9 @@ static int parse_int_cb(const char *var, const char *value, void *data)
 	return 0;
 }
 
-static int early_config_cb(const char *var, const char *value, void *vdata)
+static int early_config_cb(const char *var, const char *value,
+			   const struct config_context *ctx UNUSED,
+			   void *vdata)
 {
 	const char *key = vdata;
 
diff --git a/t/helper/test-userdiff.c b/t/helper/test-userdiff.c
index 680124a676..0ce31ce59f 100644
--- a/t/helper/test-userdiff.c
+++ b/t/helper/test-userdiff.c
@@ -12,7 +12,9 @@ static int driver_cb(struct userdiff_driver *driver,
 	return 0;
 }
 
-static int cmd__userdiff_config(const char *var, const char *value, void *cb UNUSED)
+static int cmd__userdiff_config(const char *var, const char *value,
+				const struct config_context *ctx UNUSED,
+				void *cb UNUSED)
 {
 	if (userdiff_config(var, value) < 0)
 		return -1;
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index 78cfc15d52..83bc4fd109 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -99,7 +99,8 @@ struct tr2_cfg_data {
 /*
  * See if the given config key matches any of our patterns of interest.
  */
-static int tr2_cfg_cb(const char *key, const char *value, void *d)
+static int tr2_cfg_cb(const char *key, const char *value,
+		      const struct config_context *ctx UNUSED, void *d)
 {
 	struct strbuf **s;
 	struct tr2_cfg_data *data = (struct tr2_cfg_data *)d;
@@ -142,8 +143,12 @@ void tr2_list_env_vars_fl(const char *file, int line)
 void tr2_cfg_set_fl(const char *file, int line, const char *key,
 		    const char *value)
 {
+	struct key_value_info kvi = KVI_INIT;
+	struct config_context ctx = {
+		.kvi = &kvi,
+	};
 	struct tr2_cfg_data data = { file, line };
 
 	if (tr2_cfg_load_patterns() > 0)
-		tr2_cfg_cb(key, value, &data);
+		tr2_cfg_cb(key, value, &ctx, &data);
 }
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
index 069786cb92..f26ec95ab4 100644
--- a/trace2/tr2_sysenv.c
+++ b/trace2/tr2_sysenv.c
@@ -57,7 +57,8 @@ static struct tr2_sysenv_entry tr2_sysenv_settings[] = {
 };
 /* clang-format on */
 
-static int tr2_sysenv_cb(const char *key, const char *value, void *d)
+static int tr2_sysenv_cb(const char *key, const char *value,
+			 const struct config_context *ctx UNUSED, void *d)
 {
 	int k;
 
diff --git a/trailer.c b/trailer.c
index a2c3ed6f28..06dc0b7f68 100644
--- a/trailer.c
+++ b/trailer.c
@@ -482,6 +482,7 @@ static struct {
 };
 
 static int git_trailer_default_config(const char *conf_key, const char *value,
+				      const struct config_context *ctx UNUSED,
 				      void *cb UNUSED)
 {
 	const char *trailer_item, *variable_name;
@@ -514,6 +515,7 @@ static int git_trailer_default_config(const char *conf_key, const char *value,
 }
 
 static int git_trailer_config(const char *conf_key, const char *value,
+			      const struct config_context *ctx UNUSED,
 			      void *cb UNUSED)
 {
 	const char *trailer_item, *variable_name;
diff --git a/upload-pack.c b/upload-pack.c
index d3312006a3..951fd1f9c2 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -1309,7 +1309,9 @@ static int parse_object_filter_config(const char *var, const char *value,
 	return 0;
 }
 
-static int upload_pack_config(const char *var, const char *value, void *cb_data)
+static int upload_pack_config(const char *var, const char *value,
+			      const struct config_context *ctx UNUSED,
+			      void *cb_data)
 {
 	struct upload_pack_data *data = cb_data;
 
@@ -1350,7 +1352,9 @@ static int upload_pack_config(const char *var, const char *value, void *cb_data)
 	return parse_hide_refs_config(var, value, "uploadpack", &data->hidden_refs);
 }
 
-static int upload_pack_protected_config(const char *var, const char *value, void *cb_data)
+static int upload_pack_protected_config(const char *var, const char *value,
+					const struct config_context *ctx UNUSED,
+					void *cb_data)
 {
 	struct upload_pack_data *data = cb_data;
 
diff --git a/urlmatch.c b/urlmatch.c
index eba0bdd77f..1c45f23adf 100644
--- a/urlmatch.c
+++ b/urlmatch.c
@@ -551,7 +551,8 @@ static int cmp_matches(const struct urlmatch_item *a,
 	return 0;
 }
 
-int urlmatch_config_entry(const char *var, const char *value, void *cb)
+int urlmatch_config_entry(const char *var, const char *value,
+			  const struct config_context *ctx, void *cb)
 {
 	struct string_list_item *item;
 	struct urlmatch_config *collect = cb;
@@ -565,7 +566,7 @@ int urlmatch_config_entry(const char *var, const char *value, void *cb)
 
 	if (!skip_prefix(var, collect->section, &key) || *(key++) != '.') {
 		if (collect->cascade_fn)
-			return collect->cascade_fn(var, value, cb);
+			return collect->cascade_fn(var, value, ctx, cb);
 		return 0; /* not interested */
 	}
 	dot = strrchr(key, '.');
@@ -609,7 +610,7 @@ int urlmatch_config_entry(const char *var, const char *value, void *cb)
 	strbuf_addstr(&synthkey, collect->section);
 	strbuf_addch(&synthkey, '.');
 	strbuf_addstr(&synthkey, key);
-	retval = collect->collect_fn(synthkey.buf, value, collect->cb);
+	retval = collect->collect_fn(synthkey.buf, value, ctx, collect->cb);
 
 	strbuf_release(&synthkey);
 	return retval;
diff --git a/urlmatch.h b/urlmatch.h
index bee374a642..5ba85cea13 100644
--- a/urlmatch.h
+++ b/urlmatch.h
@@ -71,7 +71,8 @@ struct urlmatch_config {
 	.vars = STRING_LIST_INIT_DUP, \
 }
 
-int urlmatch_config_entry(const char *var, const char *value, void *cb);
+int urlmatch_config_entry(const char *var, const char *value,
+			  const struct config_context *ctx, void *cb);
 void urlmatch_config_release(struct urlmatch_config *config);
 
 #endif /* URL_MATCH_H */
diff --git a/xdiff-interface.c b/xdiff-interface.c
index 0460e03f5e..dcbb5e0985 100644
--- a/xdiff-interface.c
+++ b/xdiff-interface.c
@@ -307,7 +307,8 @@ int xdiff_compare_lines(const char *l1, long s1,
 
 int git_xmerge_style = -1;
 
-int git_xmerge_config(const char *var, const char *value, void *cb)
+int git_xmerge_config(const char *var, const char *value,
+		      const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "merge.conflictstyle")) {
 		if (!value)
@@ -327,5 +328,5 @@ int git_xmerge_config(const char *var, const char *value, void *cb)
 			    value, var);
 		return 0;
 	}
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
diff --git a/xdiff-interface.h b/xdiff-interface.h
index 733c364d26..e6f80df046 100644
--- a/xdiff-interface.h
+++ b/xdiff-interface.h
@@ -50,7 +50,9 @@ int buffer_is_binary(const char *ptr, unsigned long size);
 
 void xdiff_set_find_func(xdemitconf_t *xecfg, const char *line, int cflags);
 void xdiff_clear_find_func(xdemitconf_t *xecfg);
-int git_xmerge_config(const char *var, const char *value, void *cb);
+struct config_context;
+int git_xmerge_config(const char *var, const char *value,
+		      const struct config_context *ctx, void *cb);
 extern int git_xmerge_style;
 
 /*