From: Johannes Schindelin <johannes.schinde...@gmx.de>
When we converted a `git checkout -q $onto^0` call to use
`reset_head()`, we inadvertently incurred a change from a twoway_merge
to a oneway_merge, as if we wanted a `git reset --hard` instead.
This has performance ramifications under certain, though, as the
oneway_merge needs to lstat() every single index entry whereas
twoway_merge does not.
So let's go back to the old behavior.
Signed-off-by: Johannes Schindelin <johannes.schinde...@gmx.de>
---
builtin/rebase.c | 45 ++++++++++++++++++++++++++-------------------
1 file changed, 26 insertions(+), 19 deletions(-)
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 6f6d7de156..c1cc50f3f8 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -523,11 +523,12 @@ finished_rebase:
#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
static int reset_head(struct object_id *oid, const char *action,
- const char *switch_to_branch, int detach_head,
+ const char *switch_to_branch,
+ int detach_head, int reset_hard,
const char *reflog_orig_head, const char *reflog_head)
{
struct object_id head_oid;
- struct tree_desc desc;
+ struct tree_desc desc[2];
struct lock_file lock = LOCK_INIT;
struct unpack_trees_options unpack_tree_opts;
struct tree *tree;
@@ -536,7 +537,7 @@ static int reset_head(struct object_id *oid, const char
*action,
size_t prefix_len;
struct object_id *orig = NULL, oid_orig,
*old_orig = NULL, oid_old_orig;
- int ret = 0;
+ int ret = 0, nr = 0;
if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
BUG("Not a fully qualified branch: '%s'", switch_to_branch);
@@ -544,20 +545,20 @@ static int reset_head(struct object_id *oid, const char
*action,
if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
return -1;
- if (!oid) {
- if (get_oid("HEAD", &head_oid)) {
- rollback_lock_file(&lock);
- return error(_("could not determine HEAD revision"));
- }
- oid = &head_oid;
+ if (get_oid("HEAD", &head_oid)) {
+ rollback_lock_file(&lock);
+ return error(_("could not determine HEAD revision"));
}
+ if (!oid)
+ oid = &head_oid;
+
memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
setup_unpack_trees_porcelain(&unpack_tree_opts, action);
unpack_tree_opts.head_idx = 1;
unpack_tree_opts.src_index = the_repository->index;
unpack_tree_opts.dst_index = the_repository->index;
- unpack_tree_opts.fn = oneway_merge;
+ unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
unpack_tree_opts.update = 1;
unpack_tree_opts.merge = 1;
if (!detach_head)
@@ -568,12 +569,17 @@ static int reset_head(struct object_id *oid, const char
*action,
return error(_("could not read index"));
}
- if (!fill_tree_descriptor(&desc, oid)) {
+ if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) {
+ ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
+ goto leave_reset_head;
+ }
+
+ if (!fill_tree_descriptor(&desc[nr++], oid)) {
ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
goto leave_reset_head;
}
- if (unpack_trees(1, &desc, &unpack_tree_opts)) {
+ if (unpack_trees(nr, desc, &unpack_tree_opts)) {
ret = -1;
goto leave_reset_head;
}
@@ -621,7 +627,8 @@ static int reset_head(struct object_id *oid, const char
*action,
leave_reset_head:
strbuf_release(&msg);
rollback_lock_file(&lock);
- free((void *)desc.buffer);
+ while (nr)
+ free((void *)desc[--nr].buffer);
return ret;
}
@@ -999,7 +1006,7 @@ int cmd_rebase(int argc, const char **argv, const char
*prefix)
rerere_clear(&merge_rr);
string_list_clear(&merge_rr, 1);
- if (reset_head(NULL, "reset", NULL, 0, NULL, NULL) < 0)
+ if (reset_head(NULL, "reset", NULL, 0, 1, NULL, NULL) < 0)
die(_("could not discard worktree changes"));
if (read_basic_state(&options))
exit(1);
@@ -1015,7 +1022,7 @@ int cmd_rebase(int argc, const char **argv, const char
*prefix)
if (read_basic_state(&options))
exit(1);
if (reset_head(&options.orig_head, "reset",
- options.head_name, 0, NULL, NULL) < 0)
+ options.head_name, 0, 1, NULL, NULL) < 0)
die(_("could not move back to %s"),
oid_to_hex(&options.orig_head));
ret = finish_rebase(&options);
@@ -1379,7 +1386,7 @@ int cmd_rebase(int argc, const char **argv, const char
*prefix)
write_file(autostash, "%s", oid_to_hex(&oid));
printf(_("Created autostash: %s\n"), buf.buf);
if (reset_head(&head->object.oid, "reset --hard",
- NULL, 0, NULL, NULL) < 0)
+ NULL, 0, 1, NULL, NULL) < 0)
die(_("could not reset --hard"));
printf(_("HEAD is now at %s"),
find_unique_abbrev(&head->object.oid,
@@ -1433,7 +1440,7 @@ int cmd_rebase(int argc, const char **argv, const char
*prefix)
strbuf_addf(&buf, "rebase: checkout %s",
options.switch_to);
if (reset_head(&oid, "checkout",
- options.head_name, 0,
+ options.head_name, 0, 0,
NULL, NULL) < 0) {
ret = !!error(_("could not switch to "
"%s"),
@@ -1499,7 +1506,7 @@ int cmd_rebase(int argc, const char **argv, const char
*prefix)
"it...\n"));
strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
- if (reset_head(&options.onto->object.oid, "checkout", NULL, 1,
+ if (reset_head(&options.onto->object.oid, "checkout", NULL, 1, 0,
NULL, msg.buf))
die(_("Could not detach HEAD"));
strbuf_release(&msg);
@@ -1515,7 +1522,7 @@ int cmd_rebase(int argc, const char **argv, const char
*prefix)
strbuf_addf(&msg, "rebase finished: %s onto %s",
options.head_name ? options.head_name : "detached HEAD",
oid_to_hex(&options.onto->object.oid));
- reset_head(NULL, "Fast-forwarded", options.head_name, 0,
+ reset_head(NULL, "Fast-forwarded", options.head_name, 0, 0,
"HEAD", msg.buf);
strbuf_release(&msg);
ret = !!finish_rebase(&options);
--
gitgitgadget
