tests: try git apply from subdir of toplevel

Make sure git apply can apply patches with paths relative to the
toplevel of a work tree, a subdirectory, or within the repository
metadata directory.

Relative paths are broken for most commands when run from a
subdirectory of $GIT_DIR, "git apply" being no exception.  The other
tests are meant to keep the demonstration of that company.

Based on a test by Duy.

Cc: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t4111-apply-subdir.sh b/t/t4111-apply-subdir.sh
new file mode 100755 (executable)
index 0000000..60c2237
--- /dev/null
+++ b/t/t4111-apply-subdir.sh
@@ -0,0 +1,141 @@
+#!/bin/sh
+
+test_description='patching from inconvenient places'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+       cat >patch <<-\EOF &&
+       diff file.orig file
+       --- a/file.orig
+       +++ b/file
+       @@ -1 +1,2 @@
+        1
+       +2
+       EOF
+       patch="$(pwd)/patch" &&
+
+       echo 1 >preimage &&
+       printf "%s\n" 1 2 >postimage &&
+       echo 3 >other &&
+
+       test_tick &&
+       git commit --allow-empty -m basis
+'
+
+test_expect_success 'setup: subdir' '
+       reset_subdir() {
+               git reset &&
+               mkdir -p sub/dir/b &&
+               mkdir -p objects &&
+               cp "$1" file &&
+               cp "$1" objects/file &&
+               cp "$1" sub/dir/file &&
+               cp "$1" sub/dir/b/file &&
+               git add file sub/dir/file sub/dir/b/file objects/file &&
+               cp "$2" file &&
+               cp "$2" sub/dir/file &&
+               cp "$2" sub/dir/b/file &&
+               cp "$2" objects/file
+       }
+'
+
+test_expect_success 'apply from subdir of toplevel' '
+       cp postimage expected &&
+       reset_subdir other preimage &&
+       (
+               cd sub/dir &&
+               git apply "$patch"
+       ) &&
+       test_cmp expected sub/dir/file
+'
+
+test_expect_success 'apply --cached from subdir of toplevel' '
+       cp postimage expected &&
+       cp other expected.working &&
+       reset_subdir preimage other &&
+       (
+               cd sub/dir &&
+               git apply --cached "$patch"
+       ) &&
+       git show :sub/dir/file >actual &&
+       test_cmp expected actual &&
+       test_cmp expected.working sub/dir/file
+'
+
+test_expect_success 'apply --index from subdir of toplevel' '
+       cp postimage expected &&
+       reset_subdir preimage other &&
+       (
+               cd sub/dir &&
+               test_must_fail git apply --index "$patch"
+       ) &&
+       reset_subdir other preimage &&
+       (
+               cd sub/dir &&
+               test_must_fail git apply --index "$patch"
+       ) &&
+       reset_subdir preimage preimage &&
+       (
+               cd sub/dir &&
+               git apply --index "$patch"
+       ) &&
+       git show :sub/dir/file >actual &&
+       test_cmp expected actual &&
+       test_cmp expected sub/dir/file
+'
+
+test_expect_success 'apply from .git dir' '
+       cp postimage expected &&
+       cp preimage .git/file &&
+       cp preimage .git/objects/file
+       (
+               cd .git &&
+               git apply "$patch"
+       ) &&
+       test_cmp expected .git/file
+'
+
+test_expect_failure 'apply from subdir of .git dir' '
+       cp postimage expected &&
+       cp preimage .git/file &&
+       cp preimage .git/objects/file
+       (
+               cd .git/objects &&
+               git apply "$patch"
+       ) &&
+       test_cmp expected .git/objects/file
+'
+
+test_expect_success 'apply --cached from .git dir' '
+       cp postimage expected &&
+       cp other expected.working &&
+       cp other .git/file &&
+       reset_subdir preimage other &&
+       (
+               cd .git &&
+               git apply --cached "$patch"
+       ) &&
+       git show :file >actual &&
+       test_cmp expected actual &&
+       test_cmp expected.working file &&
+       test_cmp expected.working .git/file
+'
+
+test_expect_success 'apply --cached from subdir of .git dir' '
+       cp postimage expected &&
+       cp preimage expected.subdir &&
+       cp other .git/file &&
+       cp other .git/objects/file &&
+       reset_subdir preimage other &&
+       (
+               cd .git/objects &&
+               git apply --cached "$patch"
+       ) &&
+       git show :file >actual &&
+       git show :objects/file >actual.subdir &&
+       test_cmp expected actual &&
+       test_cmp expected.subdir actual.subdir
+'
+
+test_done