From 8530c73915ab88b920411c6bbdf02ff4c396ca81 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Mon, 9 Jul 2018 15:48:19 -0400 Subject: [PATCH 1/2] sequencer: handle empty-set cases consistently If the user gives us a set that prepare_revision_walk() takes to be empty, like: git cherry-pick base..base then we report an error. It's nonsense, and there's nothing to pick. But if they use revision options that later cull the list, like: git cherry-pick --author=nobody base~2..base then we quietly create an empty todo list and return success. Arguably either behavior is acceptable, but we should definitely be consistent about it. Reporting an error seems to match the original intent, which dates all the way back to 7e2bfd3f99 (revert: allow cherry-picking more than one commit, 2010-06-02). That in turn was trying to match the single-commit case that existed before then (and which continues to issue an error). Signed-off-by: Jeff King Acked-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- sequencer.c | 6 ++++-- t/t3510-cherry-pick-sequence.sh | 7 ++++++- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/sequencer.c b/sequencer.c index 4d3f60594c..7fbacc1021 100644 --- a/sequencer.c +++ b/sequencer.c @@ -1176,8 +1176,6 @@ static int prepare_revs(struct replay_opts *opts) if (prepare_revision_walk(opts->revs)) return error(_("revision walk setup failed")); - if (!opts->revs->commits) - return error(_("empty commit set passed")); return 0; } @@ -1560,6 +1558,10 @@ static int walk_revs_populate_todo(struct todo_list *todo_list, short_commit_name(commit), subject_len, subject); unuse_commit_buffer(commit, commit_buffer); } + + if (!todo_list->nr) + return error(_("empty commit set passed")); + return 0; } diff --git a/t/t3510-cherry-pick-sequence.sh b/t/t3510-cherry-pick-sequence.sh index 0acf4b1461..6987bbfee5 100755 --- a/t/t3510-cherry-pick-sequence.sh +++ b/t/t3510-cherry-pick-sequence.sh @@ -480,11 +480,16 @@ test_expect_success 'malformed instruction sheet 2' ' test_expect_code 128 git cherry-pick --continue ' -test_expect_success 'empty commit set' ' +test_expect_success 'empty commit set (no commits to walk)' ' pristine_detach initial && test_expect_code 128 git cherry-pick base..base ' +test_expect_success 'empty commit set (culled during walk)' ' + pristine_detach initial && + test_expect_code 128 git cherry-pick -2 --author=no.such.author base +' + test_expect_success 'malformed instruction sheet 3' ' pristine_detach initial && test_expect_code 1 git cherry-pick base..anotherpick && From c5e358d07355080ea0f7a56f1edcc2f28879d9f4 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Tue, 10 Jul 2018 00:32:08 -0400 Subject: [PATCH 2/2] sequencer: don't say BUG on bogus input When cherry-picking a single commit, we go through a special code path that avoids creating a sequencer todo list at all. This path expects our revision parsing to turn up exactly one commit, and dies with a BUG if it doesn't. But it's actually quite easy to fool. For example: $ git cherry-pick --author=no.such.person HEAD error: BUG: expected exactly one commit from walk fatal: cherry-pick failed This isn't a bug; it's just bogus input. The condition to trigger this message actually has two parts: 1. We saw no commits. That's the case in the example above. Let's drop the "BUG" here to make it clear that the input is the problem. And let's also use the phrase "empty commit set passed", which matches what we say when we do a real revision walk and it turns up empty. 2. We saw more than one commit. That one _should_ be impossible to trigger, since we fed at most one tip and provided the no_walk option (and we'll have already expanded options like "--branches" that can turn into multiple tips). If this ever triggers, it's an indication that the conditional added by 7acaaac275 (revert: allow single-pick in the middle of cherry-pick sequence, 2011-12-10) needs to more carefully define the single-pick case. So this can remain a bug, but we'll upgrade it to use the BUG() macro, which would make it easier to detect and analyze if it does trigger. Signed-off-by: Jeff King Acked-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- sequencer.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/sequencer.c b/sequencer.c index 7fbacc1021..5bf91b18e2 100644 --- a/sequencer.c +++ b/sequencer.c @@ -2371,8 +2371,10 @@ int sequencer_pick_revisions(struct replay_opts *opts) if (prepare_revision_walk(opts->revs)) return error(_("revision walk setup failed")); cmit = get_revision(opts->revs); - if (!cmit || get_revision(opts->revs)) - return error("BUG: expected exactly one commit from walk"); + if (!cmit) + return error(_("empty commit set passed")); + if (get_revision(opts->revs)) + BUG("unexpected extra commit from walk"); return single_pick(cmit, opts); }