Merge branch 'cc/maint-diff-CC-binary'

* cc/maint-diff-CC-binary:
  diff: fix "git show -C -C" output when renaming a binary file

Conflicts:
	diff.c

3 files changed, 98 insertions, 5 deletions

diff --git a/diff.c b/diff.c
index c6b5fb376..2327cea5b 100644
--- a/diff.c
+++ b/diff.c
@@ -1837,6 +1837,7 @@ static void builtin_diff(const char *name_a,
 			 struct diff_filespec *one,
 			 struct diff_filespec *two,
 			 const char *xfrm_msg,
+			 int must_show_header,
 			 struct diff_options *o,
 			 int complete_rewrite)
 {
@@ -1896,16 +1897,19 @@ static void builtin_diff(const char *name_a,
 		strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
 		if (xfrm_msg)
 			strbuf_addstr(&header, xfrm_msg);
+		must_show_header = 1;
 	}
 	else if (lbl[1][0] == '/') {
 		strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
 		if (xfrm_msg)
 			strbuf_addstr(&header, xfrm_msg);
+		must_show_header = 1;
 	}
 	else {
 		if (one->mode != two->mode) {
 			strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
 			strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
+			must_show_header = 1;
 		}
 		if (xfrm_msg)
 			strbuf_addstr(&header, xfrm_msg);
@@ -1935,8 +1939,11 @@ static void builtin_diff(const char *name_a,
 			die("unable to read files to diff");
 		/* Quite common confusing case */
 		if (mf1.size == mf2.size &&
-		    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
+		    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
+			if (must_show_header)
+				fprintf(o->file, "%s", header.buf);
 			goto free_ab_and_return;
+		}
 		fprintf(o->file, "%s", header.buf);
 		strbuf_reset(&header);
 		if (DIFF_OPT_TST(o, BINARY))
@@ -1954,7 +1961,7 @@ static void builtin_diff(const char *name_a,
 		struct emit_callback ecbdata;
 		const struct userdiff_funcname *pe;
 
-		if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
+		if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
 			fprintf(o->file, "%s", header.buf);
 			strbuf_reset(&header);
 		}
@@ -2568,6 +2575,7 @@ static void fill_metainfo(struct strbuf *msg,
 			  struct diff_filespec *two,
 			  struct diff_options *o,
 			  struct diff_filepair *p,
+			  int *must_show_header,
 			  int use_color)
 {
 	const char *set = diff_get_color(use_color, DIFF_METAINFO);
@@ -2575,11 +2583,11 @@ static void fill_metainfo(struct strbuf *msg,
 	struct strbuf *msgbuf;
 	char *line_prefix = "";
 
+	*must_show_header = 1;
 	if (o->output_prefix) {
 		msgbuf = o->output_prefix(o, o->output_prefix_data);
 		line_prefix = msgbuf->buf;
 	}
-
 	strbuf_init(msg, PATH_MAX * 2 + 300);
 	switch (p->status) {
 	case DIFF_STATUS_COPIED:
@@ -2613,7 +2621,7 @@ static void fill_metainfo(struct strbuf *msg,
 		/* fallthru */
 	default:
 		/* nothing */
-		;
+		*must_show_header = 0;
 	}
 	if (one && two && hashcmp(one->sha1, two->sha1)) {
 		int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
@@ -2646,6 +2654,7 @@ static void run_diff_cmd(const char *pgm,
 {
 	const char *xfrm_msg = NULL;
 	int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
+	int must_show_header = 0;
 
 	if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
 		pgm = NULL;
@@ -2661,6 +2670,7 @@ static void run_diff_cmd(const char *pgm,
 		 * external diff driver
 		 */
 		fill_metainfo(msg, name, other, one, two, o, p,
+			      &must_show_header,
 			      DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
 		xfrm_msg = msg->len ? msg->buf : NULL;
 	}
@@ -2672,7 +2682,8 @@ static void run_diff_cmd(const char *pgm,
 	}
 	if (one && two)
 		builtin_diff(name, other ? other : name,
-			     one, two, xfrm_msg, o, complete_rewrite);
+			     one, two, xfrm_msg, must_show_header,
+			     o, complete_rewrite);
 	else
 		fprintf(o->file, "* Unmerged path %s\n", name);
 }
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index e92eab09c..935d101fe 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -438,6 +438,43 @@ test_expect_success 'whitespace-only changes not reported' '
 	test_cmp expect actual
 '
 
+cat <<EOF >expect
+diff --git a/x b/z
+similarity index NUM%
+rename from x
+rename to z
+index 380c32a..a97b785 100644
+EOF
+test_expect_success 'whitespace-only changes reported across renames' '
+	git reset --hard &&
+	for i in 1 2 3 4 5 6 7 8 9; do echo "$i$i$i$i$i$i"; done >x &&
+	git add x &&
+	git commit -m "base" &&
+	sed -e "5s/^/ /" x >z &&
+	git rm x &&
+	git add z &&
+	git diff -w -M --cached |
+	sed -e "/^similarity index /s/[0-9][0-9]*/NUM/" >actual &&
+	test_cmp expect actual
+'
+
+cat >expected <<\EOF
+diff --git a/empty b/void
+similarity index 100%
+rename from empty
+rename to void
+EOF
+
+test_expect_success 'rename empty' '
+	git reset --hard &&
+	>empty &&
+	git add empty &&
+	git commit -m empty &&
+	git mv empty void &&
+	git diff -w --cached -M >current &&
+	test_cmp expected current
+'
+
 test_expect_success 'combined diff with autocrlf conversion' '
 
 	git reset --hard &&
diff --git a/t/t4043-diff-rename-binary.sh b/t/t4043-diff-rename-binary.sh
new file mode 100755
index 000000000..06012811a
--- /dev/null
+++ b/t/t4043-diff-rename-binary.sh
@@ -0,0 +1,45 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Jakub Narebski, Christian Couder
+#
+
+test_description='Move a binary file'
+
+. ./test-lib.sh
+
+
+test_expect_success 'prepare repository' '
+	git init &&
+	echo foo > foo &&
+	echo "barQ" | q_to_nul > bar &&
+	git add . &&
+	git commit -m "Initial commit"
+'
+
+test_expect_success 'move the files into a "sub" directory' '
+	mkdir sub &&
+	git mv bar foo sub/ &&
+	git commit -m "Moved to sub/"
+'
+
+cat > expected <<\EOF
+ bar => sub/bar |  Bin 5 -> 5 bytes
+ foo => sub/foo |    0
+ 2 files changed, 0 insertions(+), 0 deletions(-)
+
+diff --git a/bar b/sub/bar
+similarity index 100%
+rename from bar
+rename to sub/bar
+diff --git a/foo b/sub/foo
+similarity index 100%
+rename from foo
+rename to sub/foo
+EOF
+
+test_expect_success 'git show -C -C report renames' '
+	git show -C -C --raw --binary --stat | tail -n 12 > current &&
+	test_cmp expected current
+'
+
+test_done