t4200: give us a clean slate after "rerere gc" tests

The "multiple identical conflicts" test counts the number of entries
in the rerere database after trying a handful of mergy operations
and recording their resolutions, but without initializing the rerere
database to a known state, allowing the state left by previous tests
to trigger a false failure.  Make it robust by cleaning the database
before it starts.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t4200-rerere.sh b/t/t4200-rerere.sh
index 1a080e782371e2d7ad489c706a54fce1553b9579..8f5f268baf3a6a74e4b3da6044aea0def006a6b8 100755 (executable)
--- a/t/t4200-rerere.sh
+++ b/t/t4200-rerere.sh
@@ -446,6 +446,8 @@ merge_conflict_resolve () {
 }
 
 test_expect_success 'multiple identical conflicts' '
+       rm -fr .git/rr-cache &&
+       mkdir .git/rr-cache &&
        git reset --hard &&
 
        test_seq 1 6 >early &&