* [PATCH v5 3/4] merge: remove global variable head[]
2011-09-17 11:57 [PATCH v5 1/4] merge: keep stash[] a local variable Nguyễn Thái Ngọc Duy
2011-09-17 11:57 ` [PATCH v5 2/4] merge: use return value of resolve_ref() to determine if HEAD is invalid Nguyễn Thái Ngọc Duy
@ 2011-09-17 11:57 ` Nguyễn Thái Ngọc Duy
2011-09-17 11:57 ` [PATCH v5 4/4] Accept tags in HEAD or MERGE_HEAD Nguyễn Thái Ngọc Duy
2 siblings, 0 replies; 5+ messages in thread
From: Nguyễn Thái Ngọc Duy @ 2011-09-17 11:57 UTC (permalink / raw)
To: git; +Cc: Junio C Hamano, Nguyễn Thái Ngọc Duy
Also kill head_invalid in favor of "head_commit == NULL".
Local variable "head" in cmd_merge() is renamed to "head_sha1" to make
sure I don't miss any access because this variable should not be used
after head_commit is set (use head_commit->object.sha1 instead).
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
builtin/merge.c | 97 ++++++++++++++++++++++++++++++-------------------------
1 files changed, 53 insertions(+), 44 deletions(-)
diff --git a/builtin/merge.c b/builtin/merge.c
index c371484..f5eb3f5 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -50,7 +50,6 @@ static int fast_forward_only;
static int allow_trivial = 1, have_message;
static struct strbuf merge_msg;
static struct commit_list *remoteheads;
-static unsigned char head[20];
static struct strategy **use_strategies;
static size_t use_strategies_nr, use_strategies_alloc;
static const char **xopts;
@@ -279,7 +278,8 @@ static void reset_hard(unsigned const char *sha1, int verbose)
die(_("read-tree failed"));
}
-static void restore_state(const unsigned char *stash)
+static void restore_state(const unsigned char *head,
+ const unsigned char *stash)
{
struct strbuf sb = STRBUF_INIT;
const char *args[] = { "stash", "apply", NULL, NULL };
@@ -309,10 +309,9 @@ static void finish_up_to_date(const char *msg)
drop_save();
}
-static void squash_message(void)
+static void squash_message(struct commit *commit)
{
struct rev_info rev;
- struct commit *commit;
struct strbuf out = STRBUF_INIT;
struct commit_list *j;
int fd;
@@ -327,7 +326,6 @@ static void squash_message(void)
rev.ignore_merges = 1;
rev.commit_format = CMIT_FMT_MEDIUM;
- commit = lookup_commit(head);
commit->object.flags |= UNINTERESTING;
add_pending_object(&rev, &commit->object, NULL);
@@ -356,9 +354,11 @@ static void squash_message(void)
strbuf_release(&out);
}
-static void finish(const unsigned char *new_head, const char *msg)
+static void finish(struct commit *head_commit,
+ const unsigned char *new_head, const char *msg)
{
struct strbuf reflog_message = STRBUF_INIT;
+ const unsigned char *head = head_commit->object.sha1;
if (!msg)
strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
@@ -369,7 +369,7 @@ static void finish(const unsigned char *new_head, const char *msg)
getenv("GIT_REFLOG_ACTION"), msg);
}
if (squash) {
- squash_message();
+ squash_message(head_commit);
} else {
if (verbosity >= 0 && !merge_msg.len)
printf(_("No merge message -- not updating HEAD\n"));
@@ -664,7 +664,7 @@ int try_merge_command(const char *strategy, size_t xopts_nr,
}
static int try_merge_strategy(const char *strategy, struct commit_list *common,
- const char *head_arg)
+ struct commit *head, const char *head_arg)
{
int index_fd;
struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
@@ -710,7 +710,7 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
commit_list_insert(j->item, &reversed);
index_fd = hold_locked_index(lock, 1);
- clean = merge_recursive(&o, lookup_commit(head),
+ clean = merge_recursive(&o, head,
remoteheads->item, reversed, &result);
if (active_cache_changed &&
(write_cache(index_fd, active_cache, active_nr) ||
@@ -861,25 +861,26 @@ static void run_prepare_commit_msg(void)
read_merge_msg();
}
-static int merge_trivial(void)
+static int merge_trivial(struct commit *head)
{
unsigned char result_tree[20], result_commit[20];
struct commit_list *parent = xmalloc(sizeof(*parent));
write_tree_trivial(result_tree);
printf(_("Wonderful.\n"));
- parent->item = lookup_commit(head);
+ parent->item = head;
parent->next = xmalloc(sizeof(*parent->next));
parent->next->item = remoteheads->item;
parent->next->next = NULL;
run_prepare_commit_msg();
commit_tree(merge_msg.buf, result_tree, parent, result_commit, NULL);
- finish(result_commit, "In-index merge");
+ finish(head, result_commit, "In-index merge");
drop_save();
return 0;
}
-static int finish_automerge(struct commit_list *common,
+static int finish_automerge(struct commit *head,
+ struct commit_list *common,
unsigned char *result_tree,
const char *wt_strategy)
{
@@ -890,12 +891,12 @@ static int finish_automerge(struct commit_list *common,
free_commit_list(common);
if (allow_fast_forward) {
parents = remoteheads;
- commit_list_insert(lookup_commit(head), &parents);
+ commit_list_insert(head, &parents);
parents = reduce_heads(parents);
} else {
struct commit_list **pptr = &parents;
- pptr = &commit_list_insert(lookup_commit(head),
+ pptr = &commit_list_insert(head,
pptr)->next;
for (j = remoteheads; j; j = j->next)
pptr = &commit_list_insert(j->item, pptr)->next;
@@ -905,7 +906,7 @@ static int finish_automerge(struct commit_list *common,
run_prepare_commit_msg();
commit_tree(merge_msg.buf, result_tree, parents, result_commit, NULL);
strbuf_addf(&buf, "Merge made by %s.", wt_strategy);
- finish(result_commit, buf.buf);
+ finish(head, result_commit, buf.buf);
strbuf_release(&buf);
drop_save();
return 0;
@@ -939,7 +940,8 @@ static int suggest_conflicts(int renormalizing)
return 1;
}
-static struct commit *is_old_style_invocation(int argc, const char **argv)
+static struct commit *is_old_style_invocation(int argc, const char **argv,
+ const unsigned char *head)
{
struct commit *second_token = NULL;
if (argc > 2) {
@@ -1012,9 +1014,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
{
unsigned char result_tree[20];
unsigned char stash[20];
+ unsigned char head_sha1[20];
+ struct commit *head_commit;
struct strbuf buf = STRBUF_INIT;
const char *head_arg;
- int flag, head_invalid = 0, i;
+ int flag, i;
int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
struct commit_list *common = NULL;
const char *best_strategy = NULL, *wt_strategy = NULL;
@@ -1027,11 +1031,16 @@ 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, 0, &flag);
+ branch = resolve_ref("HEAD", head_sha1, 0, &flag);
if (branch && !prefixcmp(branch, "refs/heads/"))
branch += 11;
- if (!branch || is_null_sha1(head))
- head_invalid = 1;
+ if (!branch || is_null_sha1(head_sha1))
+ head_commit = NULL;
+ else {
+ head_commit = lookup_commit(head_sha1);
+ if (!head_commit)
+ die(_("could not parse HEAD"));
+ }
git_config(git_merge_config, NULL);
@@ -1112,12 +1121,13 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
* additional safety measure to check for it.
*/
- if (!have_message && is_old_style_invocation(argc, argv)) {
+ if (!have_message && head_commit &&
+ is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
strbuf_addstr(&merge_msg, argv[0]);
head_arg = argv[1];
argv += 2;
argc -= 2;
- } else if (head_invalid) {
+ } else if (!head_commit) {
struct object *remote_head;
/*
* If the merged head is a valid one there is no reason
@@ -1164,7 +1174,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
}
}
- if (head_invalid || !argc)
+ if (!head_commit || !argc)
usage_with_options(builtin_merge_usage,
builtin_merge_options);
@@ -1205,17 +1215,16 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
}
if (!remoteheads->next)
- common = get_merge_bases(lookup_commit(head),
- remoteheads->item, 1);
+ common = get_merge_bases(head_commit, remoteheads->item, 1);
else {
struct commit_list *list = remoteheads;
- commit_list_insert(lookup_commit(head), &list);
+ commit_list_insert(head_commit, &list);
common = get_octopus_merge_bases(list);
free(list);
}
- update_ref("updating ORIG_HEAD", "ORIG_HEAD", head, NULL, 0,
- DIE_ON_ERR);
+ update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
+ NULL, 0, DIE_ON_ERR);
if (!common)
; /* No common ancestors found. We need a real merge. */
@@ -1229,13 +1238,13 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
return 0;
} else if (allow_fast_forward && !remoteheads->next &&
!common->next &&
- !hashcmp(common->item->object.sha1, head)) {
+ !hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
/* Again the most common case of merging one remote. */
struct strbuf msg = STRBUF_INIT;
struct object *o;
char hex[41];
- strcpy(hex, find_unique_abbrev(head, DEFAULT_ABBREV));
+ strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
if (verbosity >= 0)
printf(_("Updating %s..%s\n"),
@@ -1251,10 +1260,10 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
if (!o)
return 1;
- if (checkout_fast_forward(head, remoteheads->item->object.sha1))
+ if (checkout_fast_forward(head_commit->object.sha1, remoteheads->item->object.sha1))
return 1;
- finish(o->sha1, msg.buf);
+ finish(head_commit, o->sha1, msg.buf);
drop_save();
return 0;
} else if (!remoteheads->next && common->next)
@@ -1274,8 +1283,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
git_committer_info(IDENT_ERROR_ON_NO_NAME);
printf(_("Trying really trivial in-index merge...\n"));
if (!read_tree_trivial(common->item->object.sha1,
- head, remoteheads->item->object.sha1))
- return merge_trivial();
+ head_commit->object.sha1, remoteheads->item->object.sha1))
+ return merge_trivial(head_commit);
printf(_("Nope.\n"));
}
} else {
@@ -1294,8 +1303,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
* merge_bases again, otherwise "git merge HEAD^
* HEAD^^" would be missed.
*/
- common_one = get_merge_bases(lookup_commit(head),
- j->item, 1);
+ common_one = get_merge_bases(head_commit, j->item, 1);
if (hashcmp(common_one->item->object.sha1,
j->item->object.sha1)) {
up_to_date = 0;
@@ -1333,7 +1341,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
int ret;
if (i) {
printf(_("Rewinding the tree to pristine...\n"));
- restore_state(stash);
+ restore_state(head_commit->object.sha1, stash);
}
if (use_strategies_nr != 1)
printf(_("Trying merge strategy %s...\n"),
@@ -1345,7 +1353,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
wt_strategy = use_strategies[i]->name;
ret = try_merge_strategy(use_strategies[i]->name,
- common, head_arg);
+ common, head_commit, head_arg);
if (!option_commit && !ret) {
merge_was_ok = 1;
/*
@@ -1387,14 +1395,15 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
* auto resolved the merge cleanly.
*/
if (automerge_was_ok)
- return finish_automerge(common, result_tree, wt_strategy);
+ return finish_automerge(head_commit, common, result_tree,
+ wt_strategy);
/*
* Pick the result from the best strategy and have the user fix
* it up.
*/
if (!best_strategy) {
- restore_state(stash);
+ restore_state(head_commit->object.sha1, stash);
if (use_strategies_nr > 1)
fprintf(stderr,
_("No merge strategy handled the merge.\n"));
@@ -1406,14 +1415,14 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
; /* We already have its result in the working tree. */
else {
printf(_("Rewinding the tree to pristine...\n"));
- restore_state(stash);
+ restore_state(head_commit->object.sha1, stash);
printf(_("Using the %s to prepare resolving by hand.\n"),
best_strategy);
- try_merge_strategy(best_strategy, common, head_arg);
+ try_merge_strategy(best_strategy, common, head_commit, head_arg);
}
if (squash)
- finish(NULL, NULL);
+ finish(head_commit, NULL, NULL);
else {
int fd;
struct commit_list *j;
--
1.7.3.1.256.g2539c.dirty
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v5 4/4] Accept tags in HEAD or MERGE_HEAD
2011-09-17 11:57 [PATCH v5 1/4] merge: keep stash[] a local variable Nguyễn Thái Ngọc Duy
2011-09-17 11:57 ` [PATCH v5 2/4] merge: use return value of resolve_ref() to determine if HEAD is invalid Nguyễn Thái Ngọc Duy
2011-09-17 11:57 ` [PATCH v5 3/4] merge: remove global variable head[] Nguyễn Thái Ngọc Duy
@ 2011-09-17 11:57 ` Nguyễn Thái Ngọc Duy
2011-09-18 21:51 ` Junio C Hamano
2 siblings, 1 reply; 5+ messages in thread
From: Nguyễn Thái Ngọc Duy @ 2011-09-17 11:57 UTC (permalink / raw)
To: git; +Cc: Junio C Hamano, Nguyễn Thái Ngọc Duy
HEAD and MERGE_HEAD (among other branch tips) should never hold a
tag. That can only be caused by broken tools and is cumbersome to fix
by an end user with:
$ git update-ref HEAD $(git rev-parse HEAD^{commit})
which may look like a magic to a new person.
Be easy, warn users (so broken tools can be fixed if they bother to
report) and move on.
Be robust, if the given SHA-1 cannot be resolved to a commit object,
die (therefore return value is always valid).
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
builtin/commit.c | 6 ++++--
builtin/fmt-merge-msg.c | 2 +-
builtin/merge.c | 7 ++-----
commit.c | 12 ++++++++++++
commit.h | 7 +++++++
http-push.c | 8 ++++----
revision.c | 6 ++++--
7 files changed, 34 insertions(+), 14 deletions(-)
diff --git a/builtin/commit.c b/builtin/commit.c
index 1a65319..402eb5a 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1396,7 +1396,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
if (get_sha1("HEAD", sha1))
current_head = NULL;
else {
- current_head = lookup_commit(sha1);
+ current_head = lookup_commit_or_die(sha1, "HEAD");
if (!current_head || parse_commit(current_head))
die(_("could not parse HEAD commit"));
}
@@ -1431,6 +1431,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
pptr = &commit_list_insert(c->item, pptr)->next;
} else if (whence == FROM_MERGE) {
struct strbuf m = STRBUF_INIT;
+ struct commit *commit;
FILE *fp;
if (!reflog_msg)
@@ -1444,7 +1445,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
unsigned char sha1[20];
if (get_sha1_hex(m.buf, sha1) < 0)
die(_("Corrupt MERGE_HEAD file (%s)"), m.buf);
- pptr = &commit_list_insert(lookup_commit(sha1), pptr)->next;
+ commit = lookup_commit_or_die(sha1, "MERGE_HEAD");
+ pptr = &commit_list_insert(commit, pptr)->next;
}
fclose(fp);
strbuf_release(&m);
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 7581632..7e2f225 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -293,7 +293,7 @@ static int do_fmt_merge_msg(int merge_title, struct strbuf *in,
struct commit *head;
struct rev_info rev;
- head = lookup_commit(head_sha1);
+ head = lookup_commit_or_die(head_sha1, "HEAD");
init_revisions(&rev, NULL);
rev.commit_format = CMIT_FMT_ONELINE;
rev.ignore_merges = 1;
diff --git a/builtin/merge.c b/builtin/merge.c
index f5eb3f5..9567d60 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1036,11 +1036,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
branch += 11;
if (!branch || is_null_sha1(head_sha1))
head_commit = NULL;
- else {
- head_commit = lookup_commit(head_sha1);
- if (!head_commit)
- die(_("could not parse HEAD"));
- }
+ else
+ head_commit = lookup_commit_or_die(head_sha1, "HEAD");
git_config(git_merge_config, NULL);
diff --git a/commit.c b/commit.c
index ac337c7..50fcf96 100644
--- a/commit.c
+++ b/commit.c
@@ -39,6 +39,18 @@ struct commit *lookup_commit_reference(const unsigned char *sha1)
return lookup_commit_reference_gently(sha1, 0);
}
+struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
+{
+ struct commit *c = lookup_commit_reference(sha1);
+ if (!c)
+ die(_("could not parse %s"), ref_name);
+ if (hashcmp(sha1, c->object.sha1)) {
+ warning(_("%s %s is not a commit!"),
+ ref_name, sha1_to_hex(sha1));
+ }
+ return c;
+}
+
struct commit *lookup_commit(const unsigned char *sha1)
{
struct object *obj = lookup_object(sha1);
diff --git a/commit.h b/commit.h
index a2d571b..044134a 100644
--- a/commit.h
+++ b/commit.h
@@ -37,6 +37,13 @@ struct commit *lookup_commit_reference(const unsigned char *sha1);
struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
int quiet);
struct commit *lookup_commit_reference_by_name(const char *name);
+/*
+ * Look sha1 up for a commit, defer if needed. If dereference occurs,
+ * update "sha1" for consistency with retval->object.sha1. Also warn
+ * users this case because it is expected that sha1 points directly to
+ * a commit.
+ */
+struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name);
int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size);
int parse_commit(struct commit *item);
diff --git a/http-push.c b/http-push.c
index 28bfe76..d432b30 100644
--- a/http-push.c
+++ b/http-push.c
@@ -1606,10 +1606,10 @@ static void fetch_symref(const char *path, char **symref, unsigned char *sha1)
strbuf_release(&buffer);
}
-static int verify_merge_base(unsigned char *head_sha1, unsigned char *branch_sha1)
+static int verify_merge_base(unsigned char *head_sha1, struct ref *remote)
{
- struct commit *head = lookup_commit(head_sha1);
- struct commit *branch = lookup_commit(branch_sha1);
+ struct commit *head = lookup_commit_or_die(head_sha1, "HEAD");
+ struct commit *branch = lookup_commit_or_die(remote->old_sha1, remote->name);
struct commit_list *merge_bases = get_merge_bases(head, branch, 1);
return (merge_bases && !merge_bases->next && merge_bases->item == branch);
@@ -1680,7 +1680,7 @@ static int delete_remote_branch(const char *pattern, int force)
return error("Remote branch %s resolves to object %s\nwhich does not exist locally, perhaps you need to fetch?", remote_ref->name, sha1_to_hex(remote_ref->old_sha1));
/* Remote branch must be an ancestor of remote HEAD */
- if (!verify_merge_base(head_sha1, remote_ref->old_sha1)) {
+ if (!verify_merge_base(head_sha1, remote_ref)) {
return error("The branch '%s' is not an ancestor "
"of your current HEAD.\n"
"If you are sure you want to delete it,"
diff --git a/revision.c b/revision.c
index c46cfaa..5e057a0 100644
--- a/revision.c
+++ b/revision.c
@@ -986,10 +986,12 @@ static void prepare_show_merge(struct rev_info *revs)
const char **prune = NULL;
int i, prune_num = 1; /* counting terminating NULL */
- if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
+ if (get_sha1("HEAD", sha1))
die("--merge without HEAD?");
- if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
+ head = lookup_commit_or_die(sha1, "HEAD");
+ if (get_sha1("MERGE_HEAD", sha1))
die("--merge without MERGE_HEAD?");
+ other = lookup_commit_or_die(sha1, "MERGE_HEAD");
add_pending_object(revs, &head->object, "HEAD");
add_pending_object(revs, &other->object, "MERGE_HEAD");
bases = get_merge_bases(head, other, 1);
--
1.7.3.1.256.g2539c.dirty
^ permalink raw reply related [flat|nested] 5+ messages in thread