t3030-merge-recursive: test known breakage with empty work tree

Sometimes when working with a large repository it can be useful to try
out a merge and only check out conflicting files to disk (for example as
a speed optimization on a server).  Until v1.7.7-rc1~28^2~20
(merge-recursive: When we detect we can skip an update, actually skip
it, 2011-08-11), it was possible to do so with the following idiom:

# Prepare a temporary index and empty work tree.
GIT_INDEX_FILE="$PWD/tmp-$$-index" &&
export GIT_INDEX_FILE &&
GIT_WORK_TREE="$PWD/tmp-$$-work" &&
export GIT_WORK_TREE &&
mkdir "$GIT_WORK_TREE" &&

# Convince the index that our side is on disk.
git read-tree -i -m $ours &&
git update-index --ignore-missing --refresh &&

# Merge their side into our side.
bases=$(git merge-base --all $ours $theirs) &&
git merge-recursive $bases -- $ours $theirs &&
tree=$(git write-tree)

Nowadays, that still works and the exit status is the same, but
merge-recursive produces a diagnostic if "our" side renamed a file:

error: addinfo_cache failed for path 'dst'

Add a test to document this regression.

Signed-off-by: Brad King <brad.king@kitware.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t3030-merge-recursive.sh b/t/t3030-merge-recursive.sh
index 2f96100a5f655bbea859bf596ff9835c9abb11a2..3db3bf66517919eb3374668581906c730cc20803 100755 (executable)
--- a/t/t3030-merge-recursive.sh
+++ b/t/t3030-merge-recursive.sh
@@ -257,6 +257,7 @@ test_expect_success 'setup 8' '
        git add e &&
        test_tick &&
        git commit -m "rename a->e" &&
+       c7=$(git rev-parse --verify HEAD) &&
        git checkout rename-ln &&
        git mv a e &&
        test_ln_s_add e a &&
@@ -517,6 +518,52 @@ test_expect_success 'reset and bind merge' '
 
 '
 
+test_expect_failure 'merge-recursive w/ empty work tree - ours has rename' '
+       (
+               GIT_WORK_TREE="$PWD/ours-has-rename-work" &&
+               export GIT_WORK_TREE &&
+               GIT_INDEX_FILE="$PWD/ours-has-rename-index" &&
+               export GIT_INDEX_FILE &&
+               mkdir "$GIT_WORK_TREE" &&
+               git read-tree -i -m $c7 &&
+               git update-index --ignore-missing --refresh &&
+               git merge-recursive $c0 -- $c7 $c3 &&
+               git ls-files -s >actual-files
+       ) 2>actual-err &&
+       >expected-err &&
+       cat >expected-files <<-EOF &&
+       100644 $o3 0    b/c
+       100644 $o0 0    c
+       100644 $o0 0    d/e
+       100644 $o0 0    e
+       EOF
+       test_cmp expected-files actual-files &&
+       test_cmp expected-err actual-err
+'
+
+test_expect_success 'merge-recursive w/ empty work tree - theirs has rename' '
+       (
+               GIT_WORK_TREE="$PWD/theirs-has-rename-work" &&
+               export GIT_WORK_TREE &&
+               GIT_INDEX_FILE="$PWD/theirs-has-rename-index" &&
+               export GIT_INDEX_FILE &&
+               mkdir "$GIT_WORK_TREE" &&
+               git read-tree -i -m $c3 &&
+               git update-index --ignore-missing --refresh &&
+               git merge-recursive $c0 -- $c3 $c7 &&
+               git ls-files -s >actual-files
+       ) 2>actual-err &&
+       >expected-err &&
+       cat >expected-files <<-EOF &&
+       100644 $o3 0    b/c
+       100644 $o0 0    c
+       100644 $o0 0    d/e
+       100644 $o0 0    e
+       EOF
+       test_cmp expected-files actual-files &&
+       test_cmp expected-err actual-err
+'
+
 test_expect_success 'merge removes empty directories' '
 
        git reset --hard master &&