[PATCH] t3903 (stash): add failing test for ref of form ^{/message}

While a 'git stash show stash^{/quuxery}' works just fine, a 'git
stash pop stash^{/quuxery}' complains with: 'stash^{/quuxery} is not a
stash reference'.  This confusing behavior arises from the differences
in logic that 'show' and 'pop' internally employ to validate the
specified ref.  Document this bug by adding a failing testcase for it.

Signed-off-by: Ramkumar Ramachandra <redacted>
---
 So if you look at git-stash.sh:377, you'll notice that it's doing a
 the shell substitution "${REV%@*}" to figure out whether the stash
 ref is a valid ref.  This hacky myopic design has to be done away
 with immediately, and we should really compare the SHA-1 hex of the
 specified ref with those in the stash reflog.

 The only reason I haven't written a fix yet is because I'm not sure
 why you need this convoluted IS_STASH_LIKE and IS_STASH_REF logic in
 the first place.  Can someone enlighten me as to what is going on?

 t/t3903-stash.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 5dfbda7..04ba983 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh

@@ -583,6 +583,15 @@ test_expect_success 'invalid ref of the form stash@{n}, n >= N' '
 	git stash drop
 '
 
+test_expect_failure 'valid ref of the form stash^{/message}' '
+	git stash clear &&
+	echo bar > file &&
+	git add file &&
+	git stash save "quuxery" &&
+	git stash show stash^{/quuxery} &&
+	git stash pop stash^{/quuxery}
+'
+
 test_expect_success 'stash branch should not drop the stash if the branch exists' '
 	git stash clear &&
 	echo foo >file &&

-- 
1.8.2.1.390.g924f6c3.dirty