Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
---
2011/12/13 Junio C Hamano <gitster@xxxxxxxxx>:
> A handful of places in the existing codebase use this "two pointers"
> approach primarily for the second advantage. The way they avoid the
> disadvantage is by naming the other pointer "$something_to_free" (and the
> "$something_" part is optional if there is only one such variable in the
> context) to make it clear that the variable is not meant to be looked at
> in the code and its primary purpose is for cleaning up at the end.
>
> Perhaps renaming this "path" to "to_free" (or "path_to_free" if you want
> to hint the "path-ness" to the readers, but see below) would make it less
> likely that future tweakers mistakenly look at, modify the string thru, or
> worse yet move the pointer itself.
Thanks. The patch looks better with "_to_free" naming convention. I
learn something new today.
builtin/branch.c | 12 +++++-------
builtin/checkout.c | 15 +++++++--------
builtin/fmt-merge-msg.c | 7 ++++---
builtin/for-each-ref.c | 7 ++-----
builtin/merge.c | 12 +++++-------
builtin/notes.c | 7 ++++---
builtin/receive-pack.c | 7 +++----
builtin/show-branch.c | 4 +---
cache.h | 1 +
reflog-walk.c | 15 ++++++++-------
refs.c | 6 ++++++
wt-status.c | 4 +---
12 files changed, 47 insertions(+), 50 deletions(-)
diff --git a/builtin/branch.c b/builtin/branch.c
index e1e486e..59efe2c 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -104,6 +104,7 @@ static int branch_merged(int kind, const char *name,
*/
struct commit *reference_rev = NULL;
const char *reference_name = NULL;
+ char *reference_name_to_free = NULL;
int merged;
if (kind == REF_LOCAL_BRANCH) {
@@ -114,11 +115,9 @@ static int branch_merged(int kind, const char *name,
branch->merge &&
branch->merge[0] &&
branch->merge[0]->dst &&
- (reference_name =
- resolve_ref(branch->merge[0]->dst, sha1, 1, NULL)) != NULL) {
- reference_name = xstrdup(reference_name);
+ (reference_name = reference_name_to_free =
+ resolve_refdup(branch->merge[0]->dst, sha1, 1, NULL)) != NULL)
reference_rev = lookup_commit_reference(sha1);
- }
}
if (!reference_rev)
reference_rev = head_rev;
@@ -143,7 +142,7 @@ static int branch_merged(int kind, const char *name,
" '%s', even though it is merged to HEAD."),
name, reference_name);
}
- free((char *)reference_name);
+ free(reference_name_to_free);
return merged;
}
@@ -731,10 +730,9 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
track = git_branch_track;
- head = resolve_ref("HEAD", head_sha1, 0, NULL);
+ head = resolve_refdup("HEAD", head_sha1, 0, NULL);
if (!head)
die(_("Failed to resolve HEAD as a valid ref."));
- head = xstrdup(head);
if (!strcmp(head, "HEAD")) {
detached = 1;
} else {
diff --git a/builtin/checkout.c b/builtin/checkout.c
index b7c6302..dde44d7 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -696,17 +696,14 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
{
int ret = 0;
struct branch_info old;
+ char *path_to_free;
unsigned char rev[20];
int flag;
memset(&old, 0, sizeof(old));
- old.path = resolve_ref("HEAD", rev, 0, &flag);
- if (old.path)
- old.path = xstrdup(old.path);
+ old.path = path_to_free = resolve_refdup("HEAD", rev, 0, &flag);
old.commit = lookup_commit_reference_gently(rev, 1);
- if (!(flag & REF_ISSYMREF)) {
- free((char *)old.path);
+ if (!(flag & REF_ISSYMREF))
old.path = NULL;
- }
if (old.path && !prefixcmp(old.path, "refs/heads/"))
old.name = old.path + strlen("refs/heads/");
@@ -720,8 +717,10 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
}
ret = merge_working_tree(opts, &old, new);
- if (ret)
+ if (ret) {
+ free(path_to_free);
return ret;
+ }
if (!opts->quiet && !old.path && old.commit && new->commit != old.commit)
orphaned_commit_warning(old.commit);
@@ -729,7 +728,7 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
update_refs_for_switch(opts, &old, new);
ret = post_checkout_hook(old.commit, new->commit, 1);
- free((char *)old.path);
+ free(path_to_free);
return ret || opts->writeout_error;
}
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index bdfa0ea..e55e994 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -372,14 +372,15 @@ int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
int i = 0, pos = 0;
unsigned char head_sha1[20];
const char *current_branch;
+ char *current_branch_to_free;
/* get current branch */
- current_branch = resolve_ref("HEAD", head_sha1, 1, NULL);
+ current_branch = current_branch_to_free =
+ resolve_refdup("HEAD", head_sha1, 1, NULL);
if (!current_branch)
die("No current branch");
if (!prefixcmp(current_branch, "refs/heads/"))
current_branch += 11;
- current_branch = xstrdup(current_branch);
/* get a line */
while (pos < in->len) {
@@ -421,7 +422,7 @@ int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
}
strbuf_complete_line(out);
- free((char *)current_branch);
+ free(current_branch_to_free);
return 0;
}
diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
index d90e5d2..b01d76a 100644
--- a/builtin/for-each-ref.c
+++ b/builtin/for-each-ref.c
@@ -628,11 +628,8 @@ static void populate_value(struct refinfo *ref)
if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
unsigned char unused1[20];
- const char *symref;
- symref = resolve_ref(ref->refname, unused1, 1, NULL);
- if (symref)
- ref->symref = xstrdup(symref);
- else
+ ref->symref = resolve_refdup(ref->refname, unused1, 1, NULL);
+ if (!ref->symref)
ref->symref = "";
}
diff --git a/builtin/merge.c b/builtin/merge.c
index a1c8534..d4079e6 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1096,6 +1096,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
struct commit_list *common = NULL;
const char *best_strategy = NULL, *wt_strategy = NULL;
struct commit_list **remotes = &remoteheads;
+ char *branch_to_free;
if (argc == 2 && !strcmp(argv[1], "-h"))
usage_with_options(builtin_merge_usage, builtin_merge_options);
@@ -1104,12 +1105,9 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
* Check if we are _not_ on a detached HEAD, i.e. if there is a
* current branch.
*/
- branch = resolve_ref("HEAD", head_sha1, 0, &flag);
- if (branch) {
- if (!prefixcmp(branch, "refs/heads/"))
- branch += 11;
- branch = xstrdup(branch);
- }
+ branch = branch_to_free = resolve_refdup("HEAD", head_sha1, 0, &flag);
+ if (branch && !prefixcmp(branch, "refs/heads/"))
+ branch += 11;
if (!branch || is_null_sha1(head_sha1))
head_commit = NULL;
else
@@ -1520,6 +1518,6 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
ret = suggest_conflicts(option_renormalize);
done:
- free((char *)branch);
+ free(branch_to_free);
return ret;
}
diff --git a/builtin/notes.c b/builtin/notes.c
index 10b8bc7..11a24d7 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -804,6 +804,7 @@ static int merge_commit(struct notes_merge_options *o)
struct notes_tree *t;
struct commit *partial;
struct pretty_print_context pretty_ctx;
+ char *local_ref_to_free;
int ret;
/*
@@ -826,10 +827,10 @@ static int merge_commit(struct notes_merge_options *o)
t = xcalloc(1, sizeof(struct notes_tree));
init_notes(t, "NOTES_MERGE_PARTIAL", combine_notes_overwrite, 0);
- o->local_ref = resolve_ref("NOTES_MERGE_REF", sha1, 0, NULL);
+ o->local_ref = local_ref_to_free =
+ resolve_refdup("NOTES_MERGE_REF", sha1, 0, NULL);
if (!o->local_ref)
die("Failed to resolve NOTES_MERGE_REF");
- o->local_ref = xstrdup(o->local_ref);
if (notes_merge_commit(o, t, partial, sha1))
die("Failed to finalize notes merge");
@@ -846,7 +847,7 @@ static int merge_commit(struct notes_merge_options *o)
free_notes(t);
strbuf_release(&msg);
ret = merge_abort(o);
- free((char *)o->local_ref);
+ free(local_ref_to_free);
return ret;
}
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index b6d957c..fa251ec 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -37,6 +37,7 @@ static int prefer_ofs_delta = 1;
static int auto_update_server_info;
static int auto_gc = 1;
static const char *head_name;
+static char *head_name_to_free;
static int sent_capabilities;
static enum deny_action parse_deny_action(const char *var, const char *value)
@@ -695,10 +696,8 @@ static void execute_commands(struct command *commands, const char *unpacker_erro
check_aliased_updates(commands);
- free((char *)head_name);
- head_name = resolve_ref("HEAD", sha1, 0, NULL);
- if (head_name)
- head_name = xstrdup(head_name);
+ free(head_name_to_free);
+ head_name = head_name_to_free = resolve_refdup("HEAD", sha1, 0, NULL);
for (cmd = commands; cmd; cmd = cmd->next)
if (!cmd->skip_update)
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 4b480d7..a1f148e 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -726,10 +726,8 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
if (ac == 0) {
static const char *fake_av[2];
- const char *refname;
- refname = resolve_ref("HEAD", sha1, 1, NULL);
- fake_av[0] = xstrdup(refname);
+ fake_av[0] = resolve_refdup("HEAD", sha1, 1, NULL);
fake_av[1] = NULL;
av = fake_av;
ac = 1;
diff --git a/cache.h b/cache.h
index 8c98d05..4887a3e 100644
--- a/cache.h
+++ b/cache.h
@@ -866,6 +866,7 @@ extern int read_ref(const char *filename, unsigned char *sha1);
* errno is sometimes set on errors, but not always.
*/
extern const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag);
+extern char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag);
extern int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
diff --git a/reflog-walk.c b/reflog-walk.c
index da71a85..52eddb7 100644
--- a/reflog-walk.c
+++ b/reflog-walk.c
@@ -50,11 +50,12 @@ static struct complete_reflogs *read_complete_reflog(const char *ref)
for_each_reflog_ent(ref, read_one_reflog, reflogs);
if (reflogs->nr == 0) {
unsigned char sha1[20];
- const char *name = resolve_ref(ref, sha1, 1, NULL);
+ const char *name;
+ char *name_to_free;
+ name = name_to_free = resolve_refdup(ref, sha1, 1, NULL);
if (name) {
- name = xstrdup(name);
for_each_reflog_ent(name, read_one_reflog, reflogs);
- free((char *)name);
+ free(name_to_free);
}
}
if (reflogs->nr == 0) {
@@ -171,11 +172,11 @@ int add_reflog_for_walk(struct reflog_walk_info *info,
else {
if (*branch == '\0') {
unsigned char sha1[20];
- const char *head = resolve_ref("HEAD", sha1, 0, NULL);
- if (!head)
- die ("No current branch");
free(branch);
- branch = xstrdup(head);
+ branch = resolve_refdup("HEAD", sha1, 0, NULL);
+ if (!branch)
+ die ("No current branch");
+
}
reflogs = read_complete_reflog(branch);
if (!reflogs || reflogs->nr == 0) {
diff --git a/refs.c b/refs.c
index f5cb297..8ffb32f 100644
--- a/refs.c
+++ b/refs.c
@@ -605,6 +605,12 @@ const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *
return ref;
}
+char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
+{
+ const char *ret = resolve_ref(ref, sha1, reading, flag);
+ return ret ? xstrdup(ret) : NULL;
+}
+
/* The argument to filter_refs */
struct ref_filter {
const char *pattern;
diff --git a/wt-status.c b/wt-status.c
index 70fdb76..9ffc535 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -111,7 +111,6 @@ void status_printf_more(struct wt_status *s, const char *color,
void wt_status_prepare(struct wt_status *s)
{
unsigned char sha1[20];
- const char *head;
memset(s, 0, sizeof(*s));
memcpy(s->color_palette, default_wt_status_colors,
@@ -119,8 +118,7 @@ void wt_status_prepare(struct wt_status *s)
s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
s->use_color = -1;
s->relative_paths = 1;
- head = resolve_ref("HEAD", sha1, 0, NULL);
- s->branch = head ? xstrdup(head) : NULL;
+ s->branch = resolve_refdup("HEAD", sha1, 0, NULL);
s->reference = "HEAD";
s->fp = stdout;
s->index_file = get_index_file();
--
1.7.8.36.g69ee2
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