t/test-lib: introduce ZERO_OID

Currently we have a variable, $_z40, which contains the all-zero object
ID.  However, with NewHash, we'll have an all-zero object ID which is
longer than 40 hex characters.  In such a case, $_z40 will be a
confusing name.  Create a $ZERO_OID variable which will always reflect
the all-zeros object ID, regardless of the length of the current hash.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/test-lib.sh b/t/test-lib.sh
index fce728d2eacce38bb5ba34ff409d1ed55f6f3bd5..58c2ea52c64799a5ef7a4236fa3fcc8615c8bfed 100644 (file)
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -184,6 +184,7 @@ _x40="$_x35$_x05"
 # Zero SHA-1
 _z40=0000000000000000000000000000000000000000
 
+ZERO_OID=$_z40
 EMPTY_TREE=4b825dc642cb6eb9a060e54bf8d69288fbee4904
 EMPTY_BLOB=e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
 
@@ -195,7 +196,7 @@ LF='
 # when case-folding filenames
 u200c=$(printf '\342\200\214')
 
-export _x05 _x35 _x40 _z40 LF u200c EMPTY_TREE EMPTY_BLOB
+export _x05 _x35 _x40 _z40 LF u200c EMPTY_TREE EMPTY_BLOB ZERO_OID
 
 # Each test should start with something like this, after copyright notices:
 #