t4009: make hash size independent

Instead of hard-coding object IDs, compute them and use those in the
comparison.  Note that the comparison code ignores the actual object
IDs, but does check that they're the right size, so computing them is
the easiest way to ensure that they are.

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

t/t4009-diff-rename-4.sh

@@ -14,6 +14,7 @@ test_expect_success \
     'cat "$TEST_DIRECTORY"/diff-lib/COPYING >COPYING &&
      echo frotz >rezrov &&
     git update-index --add COPYING rezrov &&
+    orig=$(git hash-object COPYING) &&
     tree=$(git write-tree) &&
     echo $tree'
 
@@ -22,6 +23,8 @@ test_expect_success \
     'sed -e 's/HOWEVER/However/' <COPYING >COPYING.1 &&
     sed -e 's/GPL/G.P.L/g' <COPYING >COPYING.2 &&
     rm -f COPYING &&
+    c1=$(git hash-object COPYING.1) &&
+    c2=$(git hash-object COPYING.2) &&
     git update-index --add --remove COPYING COPYING.?'
 
 # tree has COPYING and rezrov.  work tree has COPYING.1 and COPYING.2,
@@ -31,11 +34,11 @@ test_expect_success \
 
 git diff-index -z -C $tree >current
 
-cat >expected <<\EOF
+cat >expected <<EOF
-:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 0603b3238a076dc6c8022aedc6648fa523a17178 C1234
+:100644 100644 $orig $c1 C1234
 COPYING
 COPYING.1
-:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 06c67961bbaed34a127f76d261f4c0bf73eda471 R1234
+:100644 100644 $orig $c2 R1234
 COPYING
 COPYING.2
 EOF
@@ -57,10 +60,10 @@ test_expect_success \
 # about rezrov.
 
 git diff-index -z -C $tree >current
-cat >expected <<\EOF
+cat >expected <<EOF
-:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 06c67961bbaed34a127f76d261f4c0bf73eda471 M
+:100644 100644 $orig $c2 M
 COPYING
-:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 0603b3238a076dc6c8022aedc6648fa523a17178 C1234
+:100644 100644 $orig $c1 C1234
 COPYING
 COPYING.1
 EOF
@@ -82,8 +85,8 @@ test_expect_success \
      git update-index --add --remove COPYING COPYING.1'
 
 git diff-index -z -C --find-copies-harder $tree >current
-cat >expected <<\EOF
+cat >expected <<EOF
-:100644 100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 0603b3238a076dc6c8022aedc6648fa523a17178 C1234
+:100644 100644 $orig $c1 C1234
 COPYING
 COPYING.1
 EOF