On Tue, Jun 04, 2019 at 12:26:14AM -0700, Elijah Newren wrote:
> Of course, this wasn't the only bug; it also showed we had a glaring
> whole in our test coverage -- there's a dearth of tests for rename/add
> conflicts, and in particular none involving content merges for the
> rename side. So, I created a patch which adds some tests for that
> (which triggered the assertion error). I pulled SZEDER's fix into the
> same patch and added a commit message explaining the issue, using a
> Based-on-patch-by tag for the fix. SZEDER: if you'd like to see this
> in a different format (maybe I add tests which show the error and then
> in a separate patch authored by you we introduce your fix?), just let
> me know.
Nah, I'm fine with it.
> Since we're at -rc3 already, even if it is a trivial patch, I'm going to
> try to re-analyze it all tomorrow to make sure I didn't miss anything and
> see if I can find more tests to throw at it.
>
> Ben: Could you rerun all your special testcases to make sure things
> are good with this patch too? It'd be much appreciated.
>
> Thanks Ben for reporting and SZEDER for jumping on and analyzing and
> cc'ing me.
>
> Sorry for the headache folks,
Thanks for the tests!
> Subject: [PATCH] merge-recursive: restore accidentally dropped setting of path
>
> In commit 8daec1df03de ("merge-recursive: switch from (oid,mode) pairs
> to a diff_filespec", 2019-04-05), we actually switched from
> (oid,mode,path) triplets to a diff_filespec -- but most callsites in the
> patch only needed to worry about oid and mode so the commit message
> focused on that. The oversight in the commit message apparently spilled
> over to the code as will; one of the dozen or so callsites accidentally
s/will/well/
> dropped the setting of the path in the conversion. Restore the path
> setting in that location.
>
> Also, this pointed out that our testsuite was lacking a good rename/add
> test, at least one that involved the need for merge content with the
> rename. Add such a test, and since rename/add vs. add/rename could
> possibly be important, redo the merge the opposite direction to make
> sure we don't have issues with the direction of the merge. These
> testcases failed before restoring the setting of path, but with the
> paths appropriately set the testcases both pass.
>
> Reported-by: Ben Humphreys <behumphreys@xxxxxxxxxxxxx>
> Based-on-patch-by: SZEDER Gábor <szeder.dev@xxxxxxxxx>
> Signed-off-by: Elijah Newren <newren@xxxxxxxxx>
> ---
> merge-recursive.c | 1 +
> t/t6042-merge-rename-corner-cases.sh | 118 +++++++++++++++++++++++++++
> 2 files changed, 119 insertions(+)
>
> diff --git a/merge-recursive.c b/merge-recursive.c
> index a7bcfcbeb4..d2e380b7ed 100644
> --- a/merge-recursive.c
> +++ b/merge-recursive.c
> @@ -1660,6 +1660,7 @@ static int handle_rename_add(struct merge_options *opt,
> c->path, add_branch);
>
> prev_path_desc = xstrfmt("version of %s from %s", path, a->path);
> + ci->ren1->src_entry->stages[other_stage].path = a->path;
> if (merge_mode_and_contents(opt, a, c,
> &ci->ren1->src_entry->stages[other_stage],
> prev_path_desc,
> diff --git a/t/t6042-merge-rename-corner-cases.sh b/t/t6042-merge-rename-corner-cases.sh
> index 09dfa8bd92..0793f64099 100755
> --- a/t/t6042-merge-rename-corner-cases.sh
> +++ b/t/t6042-merge-rename-corner-cases.sh
> @@ -411,6 +411,124 @@ test_expect_success 'disappearing dir in rename/directory conflict handled' '
> )
> '
>
> +# Test for basic rename/add-dest conflict, with rename needing content merge:
> +# Commit O: a
> +# Commit A: rename a->b, modifying b too
> +# Commit B: modify a, add different b
> +
> +test_expect_success 'setup rename-with-content-merge vs. add' '
> + test_create_repo rename-with-content-merge-and-add &&
> + (
> + cd rename-with-content-merge-and-add &&
> +
> + test_seq 1 5 >a &&
> + git add a &&
> + git commit -m O &&
> + git tag O &&
> +
> + git checkout -b A O &&
> + git mv a b &&
> + test_seq 0 5 >b &&
> + git add b &&
> + git commit -m A &&
> +
> + git checkout -b B O &&
> + echo 6 >>a &&
> + echo hello world >b &&
> + git add a b &&
> + git commit -m B
> + )
> +'
> +
> +test_expect_success 'handle rename-with-content-merge vs. add' '
> + (
> + cd rename-with-content-merge-and-add &&
> +
> + git checkout A^0 &&
> +
> + test_must_fail git merge -s recursive B^0 >out &&
> + test_i18ngrep "CONFLICT (rename/add)" out &&
> +
> + git ls-files -s >out &&
> + test_line_count = 2 out &&
> + git ls-files -u >out &&
> + test_line_count = 2 out &&
> + git ls-files -u b >out &&
Are these two 'git ls-files -u' executions as intended, i.e. first
without a file and then with 'b'?
Or is this a bit of a "Huh?!"-inducing way (for me; for you it might
be an idiom :) to check that 'b' has two unmerged entries and no other
file has unmerged entries?
> + test_line_count = 2 out &&
> + git ls-files -o >out &&
> + test_line_count = 1 out &&
> +
> + test_path_is_missing a &&
> + test_path_is_file b &&
> +
> + test_seq 0 6 >tmp &&
> + git hash-object tmp >expect &&
> + git rev-parse B:b >>expect &&
> + git rev-parse >actual \
> + :2:b :3:b &&
> + test_cmp expect actual &&
> +
> + # Test that the two-way merge in b is as expected
> + git cat-file -p :2:b >>ours &&
> + git cat-file -p :3:b >>theirs &&
> + >empty &&
> + test_must_fail git merge-file \
> + -L "HEAD" \
> + -L "" \
> + -L "B^0" \
> + ours empty theirs &&
> + git hash-object b >actual &&
> + git hash-object ours >expect &&
> + test_cmp expect actual
So these last three lines compute the object ids of two files and then
compare those two oids to make sure they match... But wouldn't a
'test_cmp ours b' do the trick just as well?
> + )
> +'
> +
> +test_expect_success 'handle rename-with-content-merge vs. add, merge other way' '
> + (
> + cd rename-with-content-merge-and-add &&
> +
> + git reset --hard &&
> + git clean -fdx &&
> +
> + git checkout B^0 &&
> +
> + test_must_fail git merge -s recursive A^0 >out &&
> + test_i18ngrep "CONFLICT (rename/add)" out &&
> +
> + git ls-files -s >out &&
> + test_line_count = 2 out &&
> + git ls-files -u >out &&
> + test_line_count = 2 out &&
> + git ls-files -u b >out &&
> + test_line_count = 2 out &&
> + git ls-files -o >out &&
> + test_line_count = 1 out &&
> +
> + test_path_is_missing a &&
> + test_path_is_file b &&
> +
> + test_seq 0 6 >tmp &&
> + git rev-parse B:b >expect &&
> + git hash-object tmp >>expect &&
> + git rev-parse >actual \
> + :2:b :3:b &&
> + test_cmp expect actual &&
> +
> + # Test that the two-way merge in b is as expected
> + git cat-file -p :2:b >>ours &&
> + git cat-file -p :3:b >>theirs &&
> + >empty &&
> + test_must_fail git merge-file \
> + -L "HEAD" \
> + -L "" \
> + -L "A^0" \
> + ours empty theirs &&
> + git hash-object b >actual &&
> + git hash-object ours >expect &&
> + test_cmp expect actual
> + )
> +'
> +
> # Test for all kinds of things that can go wrong with rename/rename (2to1):
> # Commit A: new files: a & b
> # Commit B: rename a->c, modify b
> --
> 2.22.0.rc3.1.g617c1f72bf
>
