git-merge: honor pre-merge-commit hook

git-merge does not honor the pre-commit hook when doing automatic merge
commits, and for compatibility reasons this is going to stay.

Introduce a pre-merge-commit hook which is called for an automatic merge
commit just like pre-commit is called for a non-automatic merge commit
(or any other commit).

[js: * renamed hook from "pre-merge" to "pre-merge-commit"
     * only discard the index if the hook is actually present
     * expanded githooks documentation entry
     * clarified that hook should write messages to stderr
     * squashed test changes from the original series' patch 4/4
     * modified tests to follow new pattern from this series' patch 1/4
     * added a test case for non-executable merge hooks
     * added a test case for failed merges
     * when testing that the merge hook did not run, make sure we
       actually have a merge to perform (by resetting the "side" branch
       to its original state).
     * reworded commit message
]

Improved-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Michael J Gruber
2019-08-07 11:57:07 -07:00
committed by Junio C Hamano
parent a1f3dd7eb3
commit 6098817fd7
4 changed files with 129 additions and 1 deletions

View File

@ -816,6 +816,18 @@ static void write_merge_heads(struct commit_list *);
static void prepare_to_commit(struct commit_list *remoteheads)
{
struct strbuf msg = STRBUF_INIT;
const char *index_file = get_index_file();
if (run_commit_hook(0 < option_edit, index_file, "pre-merge-commit", NULL))
abort_commit(remoteheads, NULL);
/*
* Re-read the index as pre-merge-commit hook could have updated it,
* and write it out as a tree. We must do this before we invoke
* the editor and after we invoke run_status above.
*/
if (find_hook("pre-merge-commit"))
discard_cache();
read_cache_from(index_file);
strbuf_addbuf(&msg, &merge_msg);
if (squash)
BUG("the control must not reach here under --squash");