Merge branch 'zj/diff-empty-chmod'

"git diff --stat" used to fully count a binary file with modified
execution bits whose contents is unmodified, which was not right.

By Zbigniew Jędrzejewski-Szmek (4) and Johannes Sixt (1)
* zj/diff-empty-chmod:
  t4006: Windows do not have /dev/zero
  diff --stat: do not run diff on indentical files
  diff --stat: report mode-only changes for binary files like text files
  tests: check --[short]stat output after chmod
  test: modernize style of t4006

Conflicts:
	diff.c

1 files changed, 47 insertions, 18 deletions

diff --git a/t/t4006-diff-mode.sh b/t/t4006-diff-mode.sh
index ff8c2f7532..7a3e1f9a24 100755
--- a/t/t4006-diff-mode.sh
+++ b/t/t4006-diff-mode.sh
@@ -8,23 +8,52 @@ test_description='Test mode change diffs.
 '
 . ./test-lib.sh
 
-test_expect_success \
-    'setup' \
-    'echo frotz >rezrov &&
-     git update-index --add rezrov &&
-     tree=`git write-tree` &&
-     echo $tree'
-
-test_expect_success \
-    'chmod' \
-    'test_chmod +x rezrov &&
-     git diff-index $tree >current'
-
-sed -e 's/\(:100644 100755\) \('"$_x40"'\) \2 /\1 X X /' <current >check
-echo ":100644 100755 X X M	rezrov" >expected
-
-test_expect_success \
-    'verify' \
-    'test_cmp expected check'
+sed_script='s/\(:100644 100755\) \('"$_x40"'\) \2 /\1 X X /'
+
+test_expect_success 'setup' '
+	echo frotz >rezrov &&
+	git update-index --add rezrov &&
+	tree=`git write-tree` &&
+	echo $tree
+'
+
+test_expect_success 'chmod' '
+	test_chmod +x rezrov &&
+	git diff-index $tree >current &&
+	sed -e "$sed_script" <current >check &&
+	echo ":100644 100755 X X M	rezrov" >expected &&
+	test_cmp expected check
+'
+
+test_expect_success 'prepare binary file' '
+	git commit -m rezrov &&
+	printf "\00\01\02\03\04\05\06" >binbin &&
+	git add binbin &&
+	git commit -m binbin
+'
+
+test_expect_success '--stat output after text chmod' '
+	test_chmod -x rezrov &&
+	echo " 0 files changed" >expect &&
+	git diff HEAD --stat >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--shortstat output after text chmod' '
+	git diff HEAD --shortstat >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--stat output after binary chmod' '
+	test_chmod +x binbin &&
+	echo " 0 files changed" >expect &&
+	git diff HEAD --stat >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--shortstat output after binary chmod' '
+	git diff HEAD --shortstat >actual &&
+	test_cmp expect actual
+'
 
 test_done