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git/builtin/reset.c
Junio C Hamano b3e83cc752 hold_locked_index(): align error handling with hold_lockfile_for_update() 
Callers of the hold_locked_index() function pass 0 when they want to
prepare to write a new version of the index file without wishing to
die or emit an error message when the request fails (e.g. somebody
else already held the lock), and pass 1 when they want the call to
die upon failure.

This option is called LOCK_DIE_ON_ERROR by the underlying lockfile
API, and the hold_locked_index() function translates the paramter to
LOCK_DIE_ON_ERROR when calling the hold_lock_file_for_update().

Replace these hardcoded '1' with LOCK_DIE_ON_ERROR and stop
translating.  Callers other than the ones that are replaced with
this change pass '0' to the function; no behaviour change is
intended with this patch.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

Among the callers of hold_locked_index() that passes 0:

 - diff.c::refresh_index_quietly() at the end of "git diff" is an
   opportunistic update; it leaks the lockfile structure but it is
   just before the program exits and nobody should care.

 - builtin/describe.c::cmd_describe(),
   builtin/commit.c::cmd_status(),
   sequencer.c::read_and_refresh_cache() are all opportunistic
   updates and they are OK.

 - builtin/update-index.c::cmd_update_index() takes a lock upfront
   but we may end up not needing to update the index (i.e. the
   entries may be fully up-to-date), in which case we do not need to
   issue an error upon failure to acquire the lock.  We do diagnose
   and die if we indeed need to update, so it is OK.

 - wt-status.c::require_clean_work_tree() IS BUGGY.  It asks
   silence, does not check the returned value.  Compare with
   callsites like cmd_describe() and cmd_status() to notice that it
   is wrong to call update_index_if_able() unconditionally.
2016-12-07 11:31:59 -08:00

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/*
* "git reset" builtin command
*
* Copyright (c) 2007 Carlos Rica
*
* Based on git-reset.sh, which is
*
* Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
*/
#include "builtin.h"
#include "lockfile.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "run-command.h"
#include "refs.h"
#include "diff.h"
#include "diffcore.h"
#include "tree.h"
#include "branch.h"
#include "parse-options.h"
#include "unpack-trees.h"
#include "cache-tree.h"
static const char * const git_reset_usage[] = {
N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
N_("git reset [-q] [<tree-ish>] [--] <paths>..."),
N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
NULL
};
enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
static const char *reset_type_names[] = {
N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
};
static inline int is_merge(void)
{
return !access(git_path_merge_head(), F_OK);
}
static int reset_index(const struct object_id *oid, int reset_type, int quiet)
{
int nr = 1;
struct tree_desc desc[2];
struct tree *tree;
struct unpack_trees_options opts;
memset(&opts, 0, sizeof(opts));
opts.head_idx = 1;
opts.src_index = &the_index;
opts.dst_index = &the_index;
opts.fn = oneway_merge;
opts.merge = 1;
if (!quiet)
opts.verbose_update = 1;
switch (reset_type) {
case KEEP:
case MERGE:
opts.update = 1;
break;
case HARD:
opts.update = 1;
/* fallthrough */
default:
opts.reset = 1;
}
read_cache_unmerged();
if (reset_type == KEEP) {
struct object_id head_oid;
if (get_oid("HEAD", &head_oid))
return error(_("You do not have a valid HEAD."));
if (!fill_tree_descriptor(desc, head_oid.hash))
return error(_("Failed to find tree of HEAD."));
nr++;
opts.fn = twoway_merge;
}
if (!fill_tree_descriptor(desc + nr - 1, oid->hash))
return error(_("Failed to find tree of %s."), oid_to_hex(oid));
if (unpack_trees(nr, desc, &opts))
return -1;
if (reset_type == MIXED || reset_type == HARD) {
tree = parse_tree_indirect(oid->hash);
prime_cache_tree(&the_index, tree);
}
return 0;
}
static void print_new_head_line(struct commit *commit)
{
const char *hex, *body;
const char *msg;
hex = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
printf(_("HEAD is now at %s"), hex);
msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
body = strstr(msg, "\n\n");
if (body) {
const char *eol;
size_t len;
body = skip_blank_lines(body + 2);
eol = strchr(body, '\n');
len = eol ? eol - body : strlen(body);
printf(" %.*s\n", (int) len, body);
}
else
printf("\n");
unuse_commit_buffer(commit, msg);
}
static void update_index_from_diff(struct diff_queue_struct *q,
struct diff_options *opt, void *data)
{
int i;
int intent_to_add = *(int *)data;
for (i = 0; i < q->nr; i++) {
struct diff_filespec *one = q->queue[i]->one;
int is_missing = !(one->mode && !is_null_oid(&one->oid));
struct cache_entry *ce;
if (is_missing && !intent_to_add) {
remove_file_from_cache(one->path);
continue;
}
ce = make_cache_entry(one->mode, one->oid.hash, one->path,
0, 0);
if (!ce)
die(_("make_cache_entry failed for path '%s'"),
one->path);
if (is_missing) {
ce->ce_flags |= CE_INTENT_TO_ADD;
set_object_name_for_intent_to_add_entry(ce);
}
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
}
}
static int read_from_tree(const struct pathspec *pathspec,
struct object_id *tree_oid,
int intent_to_add)
{
struct diff_options opt;
memset(&opt, 0, sizeof(opt));
copy_pathspec(&opt.pathspec, pathspec);
opt.output_format = DIFF_FORMAT_CALLBACK;
opt.format_callback = update_index_from_diff;
opt.format_callback_data = &intent_to_add;
if (do_diff_cache(tree_oid->hash, &opt))
return 1;
diffcore_std(&opt);
diff_flush(&opt);
clear_pathspec(&opt.pathspec);
return 0;
}
static void set_reflog_message(struct strbuf *sb, const char *action,
const char *rev)
{
const char *rla = getenv("GIT_REFLOG_ACTION");
strbuf_reset(sb);
if (rla)
strbuf_addf(sb, "%s: %s", rla, action);
else if (rev)
strbuf_addf(sb, "reset: moving to %s", rev);
else
strbuf_addf(sb, "reset: %s", action);
}
static void die_if_unmerged_cache(int reset_type)
{
if (is_merge() || unmerged_cache())
die(_("Cannot do a %s reset in the middle of a merge."),
_(reset_type_names[reset_type]));
}
static void parse_args(struct pathspec *pathspec,
const char **argv, const char *prefix,
int patch_mode,
const char **rev_ret)
{
const char *rev = "HEAD";
struct object_id unused;
/*
* Possible arguments are:
*
* git reset [-opts] [<rev>]
* git reset [-opts] <tree> [<paths>...]
* git reset [-opts] <tree> -- [<paths>...]
* git reset [-opts] -- [<paths>...]
* git reset [-opts] <paths>...
*
* At this point, argv points immediately after [-opts].
*/
if (argv[0]) {
if (!strcmp(argv[0], "--")) {
argv++; /* reset to HEAD, possibly with paths */
} else if (argv[1] && !strcmp(argv[1], "--")) {
rev = argv[0];
argv += 2;
}
/*
* Otherwise, argv[0] could be either <rev> or <paths> and
* has to be unambiguous. If there is a single argument, it
* can not be a tree
*/
else if ((!argv[1] && !get_sha1_committish(argv[0], unused.hash)) ||
(argv[1] && !get_sha1_treeish(argv[0], unused.hash))) {
/*
* Ok, argv[0] looks like a commit/tree; it should not
* be a filename.
*/
verify_non_filename(prefix, argv[0]);
rev = *argv++;
} else {
/* Otherwise we treat this as a filename */
verify_filename(prefix, argv[0], 1);
}
}
*rev_ret = rev;
if (read_cache() < 0)
die(_("index file corrupt"));
parse_pathspec(pathspec, 0,
PATHSPEC_PREFER_FULL |
PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP |
(patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
prefix, argv);
}
static int reset_refs(const char *rev, const struct object_id *oid)
{
int update_ref_status;
struct strbuf msg = STRBUF_INIT;
struct object_id *orig = NULL, oid_orig,
*old_orig = NULL, oid_old_orig;
if (!get_oid("ORIG_HEAD", &oid_old_orig))
old_orig = &oid_old_orig;
if (!get_oid("HEAD", &oid_orig)) {
orig = &oid_orig;
set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
update_ref_oid(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
UPDATE_REFS_MSG_ON_ERR);
} else if (old_orig)
delete_ref("ORIG_HEAD", old_orig->hash, 0);
set_reflog_message(&msg, "updating HEAD", rev);
update_ref_status = update_ref_oid(msg.buf, "HEAD", oid, orig, 0,
UPDATE_REFS_MSG_ON_ERR);
strbuf_release(&msg);
return update_ref_status;
}
int cmd_reset(int argc, const char **argv, const char *prefix)
{
int reset_type = NONE, update_ref_status = 0, quiet = 0;
int patch_mode = 0, unborn;
const char *rev;
struct object_id oid;
struct pathspec pathspec;
int intent_to_add = 0;
const struct option options[] = {
OPT__QUIET(&quiet, N_("be quiet, only report errors")),
OPT_SET_INT(0, "mixed", &reset_type,
N_("reset HEAD and index"), MIXED),
OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
OPT_SET_INT(0, "hard", &reset_type,
N_("reset HEAD, index and working tree"), HARD),
OPT_SET_INT(0, "merge", &reset_type,
N_("reset HEAD, index and working tree"), MERGE),
OPT_SET_INT(0, "keep", &reset_type,
N_("reset HEAD but keep local changes"), KEEP),
OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
OPT_BOOL('N', "intent-to-add", &intent_to_add,
N_("record only the fact that removed paths will be added later")),
OPT_END()
};
git_config(git_default_config, NULL);
argc = parse_options(argc, argv, prefix, options, git_reset_usage,
PARSE_OPT_KEEP_DASHDASH);
parse_args(&pathspec, argv, prefix, patch_mode, &rev);
unborn = !strcmp(rev, "HEAD") && get_sha1("HEAD", oid.hash);
if (unborn) {
/* reset on unborn branch: treat as reset to empty tree */
hashcpy(oid.hash, EMPTY_TREE_SHA1_BIN);
} else if (!pathspec.nr) {
struct commit *commit;
if (get_sha1_committish(rev, oid.hash))
die(_("Failed to resolve '%s' as a valid revision."), rev);
commit = lookup_commit_reference(oid.hash);
if (!commit)
die(_("Could not parse object '%s'."), rev);
oidcpy(&oid, &commit->object.oid);
} else {
struct tree *tree;
if (get_sha1_treeish(rev, oid.hash))
die(_("Failed to resolve '%s' as a valid tree."), rev);
tree = parse_tree_indirect(oid.hash);
if (!tree)
die(_("Could not parse object '%s'."), rev);
oidcpy(&oid, &tree->object.oid);
}
if (patch_mode) {
if (reset_type != NONE)
die(_("--patch is incompatible with --{hard,mixed,soft}"));
return run_add_interactive(rev, "--patch=reset", &pathspec);
}
/* git reset tree [--] paths... can be used to
* load chosen paths from the tree into the index without
* affecting the working tree nor HEAD. */
if (pathspec.nr) {
if (reset_type == MIXED)
warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
else if (reset_type != NONE)
die(_("Cannot do %s reset with paths."),
_(reset_type_names[reset_type]));
}
if (reset_type == NONE)
reset_type = MIXED; /* by default */
if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
setup_work_tree();
if (reset_type == MIXED && is_bare_repository())
die(_("%s reset is not allowed in a bare repository"),
_(reset_type_names[reset_type]));
if (intent_to_add && reset_type != MIXED)
die(_("-N can only be used with --mixed"));
/* Soft reset does not touch the index file nor the working tree
* at all, but requires them in a good order. Other resets reset
* the index file to the tree object we are switching to. */
if (reset_type == SOFT || reset_type == KEEP)
die_if_unmerged_cache(reset_type);
if (reset_type != SOFT) {
struct lock_file *lock = xcalloc(1, sizeof(*lock));
hold_locked_index(lock, LOCK_DIE_ON_ERROR);
if (reset_type == MIXED) {
int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
if (read_from_tree(&pathspec, &oid, intent_to_add))
return 1;
if (get_git_work_tree())
refresh_index(&the_index, flags, NULL, NULL,
_("Unstaged changes after reset:"));
} else {
int err = reset_index(&oid, reset_type, quiet);
if (reset_type == KEEP && !err)
err = reset_index(&oid, MIXED, quiet);
if (err)
die(_("Could not reset index file to revision '%s'."), rev);
}
if (write_locked_index(&the_index, lock, COMMIT_LOCK))
die(_("Could not write new index file."));
}
if (!pathspec.nr && !unborn) {
/* Any resets without paths update HEAD to the head being
* switched to, saving the previous head in ORIG_HEAD before. */
update_ref_status = reset_refs(rev, &oid);
if (reset_type == HARD && !update_ref_status && !quiet)
print_new_head_line(lookup_commit_reference(oid.hash));
}
if (!pathspec.nr)
remove_branch_state();
return update_ref_status;
}
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