help: use command-list.txt for the source of guides

The help command currently hard codes the list of guides and their
summary in C. Let's move this list to command-list.txt. This lets us
extract summary lines from Documentation/git*.txt. This also
potentially lets us list guides in git.txt, but I'll leave that for
now.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/gitattributes.txt

@@ -3,7 +3,7 @@ gitattributes(5)
 
 NAME
 ----
-gitattributes - defining attributes per path
+gitattributes - Defining attributes per path
 
 SYNOPSIS
 --------

Documentation/gitmodules.txt

@@ -3,7 +3,7 @@ gitmodules(5)
 
 NAME
 ----
-gitmodules - defining submodule properties
+gitmodules - Defining submodule properties
 
 SYNOPSIS
 --------

Documentation/gitrevisions.txt

@@ -3,7 +3,7 @@ gitrevisions(7)
 
 NAME
 ----
-gitrevisions - specifying revisions and ranges for Git
+gitrevisions - Specifying revisions and ranges for Git
 
 SYNOPSIS
 --------

Makefile

@@ -1937,7 +1937,7 @@ $(BUILT_INS): git$X
 
 command-list.h: generate-cmdlist.sh command-list.txt
 
-command-list.h: $(wildcard Documentation/git-*.txt)
+command-list.h: $(wildcard Documentation/git*.txt)
 	$(QUIET_GEN)$(SHELL_PATH) ./generate-cmdlist.sh command-list.txt >$@+ && mv $@+ $@
 
 SCRIPT_DEFINES = $(SHELL_PATH_SQ):$(DIFF_SQ):$(GIT_VERSION):\

builtin/help.c

@@ -402,38 +402,6 @@ static void show_html_page(const char *git_cmd)
 	open_html(page_path.buf);
 }
 
-static struct {
-	const char *name;
-	const char *help;
-} common_guides[] = {
-	{ "attributes", N_("Defining attributes per path") },
-	{ "everyday", N_("Everyday Git With 20 Commands Or So") },
-	{ "glossary", N_("A Git glossary") },
-	{ "ignore", N_("Specifies intentionally untracked files to ignore") },
-	{ "modules", N_("Defining submodule properties") },
-	{ "revisions", N_("Specifying revisions and ranges for Git") },
-	{ "tutorial", N_("A tutorial introduction to Git (for version 1.5.1 or newer)") },
-	{ "workflows", N_("An overview of recommended workflows with Git") },
-};
-
-static void list_common_guides_help(void)
-{
-	int i, longest = 0;
-
-	for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
-		if (longest < strlen(common_guides[i].name))
-			longest = strlen(common_guides[i].name);
-	}
-
-	puts(_("The common Git guides are:\n"));
-	for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
-		printf("   %s   ", common_guides[i].name);
-		mput_char(' ', longest - strlen(common_guides[i].name));
-		puts(_(common_guides[i].help));
-	}
-	putchar('\n');
-}
-
 static const char *check_git_cmd(const char* cmd)
 {
 	char *alias;

command-list.txt

@@ -139,3 +139,19 @@ gitweb                                  ancillaryinterrogators
 git-whatchanged                         ancillaryinterrogators
 git-worktree                            mainporcelain
 git-write-tree                          plumbingmanipulators
+gitattributes                           guide
+gitcli                                  guide
+gitcore-tutorial                        guide
+gitcvs-migration                        guide
+gitdiffcore                             guide
+giteveryday                             guide
+gitglossary                             guide
+githooks                                guide
+gitignore                               guide
+gitmodules                              guide
+gitnamespaces                           guide
+gitrepository-layout                    guide
+gitrevisions                            guide
+gittutorial-2                           guide
+gittutorial                             guide
+gitworkflows                            guide

contrib/completion/git-completion.bash

@@ -1575,6 +1575,13 @@ _git_grep ()
 	__git_complete_refs
 }
 
+__git_all_guides=
+__git_compute_all_guides ()
+{
+	test -n "$__git_all_guides" ||
+	__git_all_guides=$(git --list-cmds=list-guide)
+}
+
 _git_help ()
 {
 	case "$cur" in
@@ -1584,11 +1591,9 @@ _git_help ()
 		;;
 	esac
 	__git_compute_all_commands
-	__gitcomp "$__git_all_commands $(__git_aliases)
-		attributes cli core-tutorial cvs-migration
-		diffcore everyday gitk glossary hooks ignore modules
-		namespaces repository-layout revisions tutorial tutorial-2
-		workflows
+	__git_compute_all_guides
+	__gitcomp "$__git_all_commands $(__git_aliases) $__git_all_guides
+		gitk
 		"
 }
 

help.c

@@ -39,12 +39,14 @@ static struct category_description main_categories[] = {
 	{ 0, NULL }
 };
 
-static const char *drop_prefix(const char *name)
+static const char *drop_prefix(const char *name, uint32_t category)
 {
 	const char *new_name;
 
 	if (skip_prefix(name, "git-", &new_name))
 		return new_name;
+	if (category == CAT_guide && skip_prefix(name, "git", &new_name))
+		return new_name;
 	return name;
 
 }
@@ -66,7 +68,7 @@ static void extract_cmds(struct cmdname_help **p_cmds, uint32_t mask)
 			continue;
 
 		cmds[nr] = *cmd;
-		cmds[nr].name = drop_prefix(cmd->name);
+		cmds[nr].name = drop_prefix(cmd->name, cmd->category);
 
 		nr++;
 	}
@@ -358,11 +360,22 @@ void list_cmds_by_category(struct string_list *list,
 	for (i = 0; i < n; i++) {
 		struct cmdname_help *cmd = command_list + i;
 
-		if (cmd->category & cat_id)
-			string_list_append(list, drop_prefix(cmd->name));
+		if (!(cmd->category & cat_id))
+			continue;
+		string_list_append(list, drop_prefix(cmd->name, cmd->category));
 	}
 }
 
+void list_common_guides_help(void)
+{
+	struct category_description catdesc[] = {
+		{ CAT_guide, N_("The common Git guides are:") },
+		{ 0, NULL }
+	};
+	print_cmd_by_category(catdesc);
+	putchar('\n');
+}
+
 void list_all_cmds_help(void)
 {
 	print_cmd_by_category(main_categories);

help.h

@@ -20,6 +20,7 @@ static inline void mput_char(char c, unsigned int num)
 
 extern void list_common_cmds_help(void);
 extern void list_all_cmds_help(void);
+extern void list_common_guides_help(void);
 
 extern void list_all_main_cmds(struct string_list *list);
 extern void list_all_other_cmds(struct string_list *list);

t/t0012-help.sh

@@ -66,6 +66,12 @@ test_expect_success 'git help' '
 	test_i18ngrep "^   commit " help.output &&
 	test_i18ngrep "^   fetch  " help.output
 '
+test_expect_success 'git help -g' '
+	git help -g >help.output &&
+	test_i18ngrep "^   attributes " help.output &&
+	test_i18ngrep "^   everyday   " help.output &&
+	test_i18ngrep "^   tutorial   " help.output
+'
 
 test_expect_success 'generate builtin list' '
 	git --list-cmds=builtins >builtins