4 files changed, 14 insertions, 5 deletions
diff --git a/t/diff-lib.sh b/t/diff-lib.sh
index a912f43..745a1b0 100755
--- a/t/diff-lib.sh
+++ b/t/diff-lib.sh
@@ -29,7 +29,13 @@ compare_diff_raw_z () {
 compare_diff_patch () {
     # When heuristics are improved, the score numbers would change.
     # Ignore them while comparing.
-    sed -e '/^[dis]*imilarity index [0-9]*%$/d' <"$1" >.tmp-1
-    sed -e '/^[dis]*imilarity index [0-9]*%$/d' <"$2" >.tmp-2
+    sed -e '
+	/^[dis]*imilarity index [0-9]*%$/d
+	/^index [0-9a-f]*\.\.[0-9a-f]/d
+    ' <"$1" >.tmp-1
+    sed -e '
+	/^[dis]*imilarity index [0-9]*%$/d
+	/^index [0-9a-f]*\.\.[0-9a-f]/d
+    ' <"$2" >.tmp-2
     diff -u .tmp-1 .tmp-2 && rm -f .tmp-1 .tmp-2
 }
diff --git a/t/t4000-diff-format.sh b/t/t4000-diff-format.sh
index f3b6330..beb6d8f 100755
--- a/t/t4000-diff-format.sh
+++ b/t/t4000-diff-format.sh
@@ -7,6 +7,7 @@ test_description='Test built-in diff output engine.
 
 '
 . ./test-lib.sh
+. ../diff-lib.sh
 
 echo >path0 'Line 1
 Line 2
@@ -48,6 +49,6 @@ EOF
 
 test_expect_success \
     'validate git-diff-files -p output.' \
-    'cmp -s current expected'
+    'compare_diff_patch current expected'
 
 test_done
diff --git a/t/t4001-diff-rename.sh b/t/t4001-diff-rename.sh
index be47485..2e3c20d 100755
--- a/t/t4001-diff-rename.sh
+++ b/t/t4001-diff-rename.sh
@@ -7,6 +7,7 @@ test_description='Test rename detection in diff engine.
 
 '
 . ./test-lib.sh
+. ../diff-lib.sh
 
 echo >path0 'Line 1
 Line 2
@@ -61,6 +62,6 @@ EOF
 
 test_expect_success \
     'validate the output.' \
-    'diff -I "similarity.*" >/dev/null current expected'
+    'compare_diff_patch current expected'
 
 test_done
diff --git a/t/t4004-diff-rename-symlink.sh b/t/t4004-diff-rename-symlink.sh
index f59614a..a23aaa0 100755
--- a/t/t4004-diff-rename-symlink.sh
+++ b/t/t4004-diff-rename-symlink.sh
@@ -10,6 +10,7 @@ copy of symbolic links, but should not produce rename/copy followed
 by an edit for them.
 '
 . ./test-lib.sh
+. ../diff-lib.sh
 
 test_expect_success \
     'prepare reference tree' \
@@ -61,6 +62,6 @@ EOF
 
 test_expect_success \
     'validate diff output' \
-    'diff -u current expected'
+    'compare_diff_patch current expected'
 
 test_done