From 5da69c0dacb65cf80fc80b53e652fefad7469bf1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Antti=20Ker=C3=A4nen?= Date: Thu, 13 Aug 2020 20:42:57 +0300 Subject: [PATCH] rebase -i: fix possibly wrong onto hash in todo MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 'todo_list_write_to_file' may overwrite the static buffer, originating from 'find_unique_abbrev', that was used to store the short commit hash 'c' for "# Rebase a..b onto c" message in the todo editor. This is because the buffer that is returned from 'find_unique_abbrev' is valid until 4 more calls to `find_unique_abbrev` are made. As 'todo_list_write_to_file' calls 'find_unique_abbrev' for each rebased commit, the hash for 'c' is overwritten if there are 4 or more commits in the rebase. This behavior has been broken since its introduction. Fix by storing the short onto commit hash in a different buffer that remains valid, before calling 'todo_list_write_to_file'. Found-by: Jussi Keränen Signed-off-by: Antti Keränen Acked-by: Alban Gruin Signed-off-by: Junio C Hamano --- sequencer.c | 5 +++-- t/t3404-rebase-interactive.sh | 6 ++++++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/sequencer.c b/sequencer.c index fd7701c88a..e2007dbb8c 100644 --- a/sequencer.c +++ b/sequencer.c @@ -5178,13 +5178,14 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla struct string_list *commands, unsigned autosquash, struct todo_list *todo_list) { - const char *shortonto, *todo_file = rebase_path_todo(); + char shortonto[GIT_MAX_HEXSZ + 1]; + const char *todo_file = rebase_path_todo(); struct todo_list new_todo = TODO_LIST_INIT; struct strbuf *buf = &todo_list->buf, buf2 = STRBUF_INIT; struct object_id oid = onto->object.oid; int res; - shortonto = find_unique_abbrev(&oid, DEFAULT_ABBREV); + find_unique_abbrev_r(shortonto, &oid, DEFAULT_ABBREV); if (buf->len == 0) { struct todo_item *item = append_new_todo(todo_list); diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh index 4a7d21f898..1b4fa0843e 100755 --- a/t/t3404-rebase-interactive.sh +++ b/t/t3404-rebase-interactive.sh @@ -1760,6 +1760,12 @@ test_expect_success 'correct error message for commit --amend after empty pick' test_i18ngrep "middle of a rebase -- cannot amend." err ' +test_expect_success 'todo has correct onto hash' ' + GIT_SEQUENCE_EDITOR=cat git rebase -i no-conflict-branch~4 no-conflict-branch >actual && + onto=$(git rev-parse --short HEAD~4) && + test_i18ngrep "^# Rebase ..* onto $onto" actual +' + # This must be the last test in this file test_expect_success '$EDITOR and friends are unchanged' ' test_editor_unchanged