From: Michael Lohmann <mi.al.lohmann@xxxxxxxxx>
'git log' learned in ae3e5e1ef2 (git log -p --merge [[--] paths...],
2006-07-03) to show commits touching conflicted files in the range
HEAD...MERGE_HEAD, an addition documented in d249b45547 (Document
rev-list's option --merge, 2006-08-04).
It can be useful to look at the commit history to understand what lead
to merge conflicts also for other mergy operations besides merges, like
cherry-pick, revert and rebase.
For rebases, an interesting range to look at is HEAD...REBASE_HEAD,
since the conflicts are usually caused by how the code changed
differently on HEAD since REBASE_HEAD forked from it.
For cherry-picks and revert, it is less clear that
HEAD...CHERRY_PICK_HEAD and HEAD...REVERT_HEAD are indeed interesting
ranges, since these commands are about applying or unapplying a single
(or a few, for cherry-pick) commit(s) on top of HEAD. However, conflicts
encountered during these operations can indeed be caused by changes
introduced in preceding commits on both sides of the history.
Adjust the code in prepare_show_merge so it constructs the range
HEAD...$OTHER for each of OTHER={MERGE_HEAD, CHERRY_PICK_HEAD,
REVERT_HEAD or REBASE_HEAD}. Note that we try these pseudorefs in order,
so keep REBASE_HEAD last since the three other operations can be
performed during a rebase. Note also that in the uncommon case where
$OTHER and HEAD do not share a common ancestor, this will show the
complete histories of both sides since their root commits, which is the
same behaviour as currently happens in that case for HEAD and
MERGE_HEAD.
Adjust the documentation of this option accordingly.
Co-authored-by: Philippe Blain <levraiphilippeblain@xxxxxxxxx>
Co-authored-by: Johannes Sixt <j6t@xxxxxxxx>
Signed-off-by: Philippe Blain <levraiphilippeblain@xxxxxxxxx>
Signed-off-by: Michael Lohmann <mi.al.lohmann@xxxxxxxxx>
[jc: tweaked in j6t's precedence fix that tries REBASE_HEAD last]
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
Documentation/gitk.txt | 8 ++++----
Documentation/rev-list-options.txt | 6 ++++--
revision.c | 31 +++++++++++++++++++++++--------
3 files changed, 31 insertions(+), 14 deletions(-)
diff --git a/Documentation/gitk.txt b/Documentation/gitk.txt
index c2213bb77b..80ff4e149a 100644
--- a/Documentation/gitk.txt
+++ b/Documentation/gitk.txt
@@ -63,10 +63,10 @@ linkgit:git-rev-list[1] for a complete list.
--merge::
- After an attempt to merge stops with conflicts, show the commits on
- the history between two branches (i.e. the HEAD and the MERGE_HEAD)
- that modify the conflicted files and do not exist on all the heads
- being merged.
+ Show commits touching conflicted paths in the range `HEAD...$OTHER`,
+ where `$OTHER` is the first existing pseudoref in `MERGE_HEAD`,
+ `CHERRY_PICK_HEAD`, `REVERT_HEAD` or `REBASE_HEAD`. Only works
+ when the index has unmerged entries.
--left-right::
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 2bf239ff03..5b4672c346 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -341,8 +341,10 @@ See also linkgit:git-reflog[1].
Under `--pretty=reference`, this information will not be shown at all.
--merge::
- After a failed merge, show refs that touch files having a
- conflict and don't exist on all heads to merge.
+ Show commits touching conflicted paths in the range `HEAD...$OTHER`,
+ where `$OTHER` is the first existing pseudoref in `MERGE_HEAD`,
+ `CHERRY_PICK_HEAD`, `REVERT_HEAD` or `REBASE_HEAD`. Only works
+ when the index has unmerged entries.
--boundary::
Output excluded boundary commits. Boundary commits are
diff --git a/revision.c b/revision.c
index aa4c4dc778..36dc2f94f7 100644
--- a/revision.c
+++ b/revision.c
@@ -1961,11 +1961,31 @@ static void add_pending_commit_list(struct rev_info *revs,
}
}
+static const char *lookup_other_head(struct object_id *oid)
+{
+ int i;
+ static const char *const other_head[] = {
+ "MERGE_HEAD", "CHERRY_PICK_HEAD", "REVERT_HEAD", "REBASE_HEAD"
+ };
+
+ for (i = 0; i < ARRAY_SIZE(other_head); i++)
+ if (!read_ref_full(other_head[i],
+ RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
+ oid, NULL)) {
+ if (is_null_oid(oid))
+ die("%s is a symbolic ref???", other_head[i]);
+ return other_head[i];
+ }
+
+ die("--merge without MERGE_HEAD, CHERRY_PICK_HEAD, REVERT_HEAD or REBASE_HEAD?");
+}
+
static void prepare_show_merge(struct rev_info *revs)
{
struct commit_list *bases;
struct commit *head, *other;
struct object_id oid;
+ const char *other_name;
const char **prune = NULL;
int i, prune_num = 1; /* counting terminating NULL */
struct index_state *istate = revs->repo->index;
@@ -1973,15 +1993,10 @@ static void prepare_show_merge(struct rev_info *revs)
if (repo_get_oid(the_repository, "HEAD", &oid))
die("--merge without HEAD?");
head = lookup_commit_or_die(&oid, "HEAD");
- if (read_ref_full("MERGE_HEAD",
- RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
- &oid, NULL))
- die("--merge without MERGE_HEAD?");
- if (is_null_oid(&oid))
- die("MERGE_HEAD is a symbolic ref???");
- other = lookup_commit_or_die(&oid, "MERGE_HEAD");
+ other_name = lookup_other_head(&oid);
+ other = lookup_commit_or_die(&oid, other_name);
add_pending_object(revs, &head->object, "HEAD");
- add_pending_object(revs, &other->object, "MERGE_HEAD");
+ add_pending_object(revs, &other->object, other_name);
bases = repo_get_merge_bases(the_repository, head, other);
add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
--
2.39.1
