diff: correct newline in summary for renamed files

In 146fdb0dfe (diff.c: emit_diff_symbol learns about DIFF_SYMBOL_SUMMARY,
2017-06-29), the conversion from direct printing to the symbol emission
dropped the new line character for renamed, copied and rewritten files.

Add the emission of a newline, add a test for this case.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.c

@@ -5251,6 +5251,7 @@ static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
 			strbuf_addch(&sb, ' ');
 			quote_c_style(p->two->path, &sb, NULL, 0);
 		}
+		strbuf_addch(&sb, '\n');
 		emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
 				 sb.buf, sb.len, 0);
 		strbuf_release(&sb);

t/t4013-diff-various.sh

@@ -90,6 +90,14 @@ test_expect_success setup '
 	git commit -m "Rearranged lines in dir/sub" &&
 	git checkout master &&
 
+	GIT_AUTHOR_DATE="2006-06-26 00:06:00 +0000" &&
+	GIT_COMMITTER_DATE="2006-06-26 00:06:00 +0000" &&
+	export GIT_AUTHOR_DATE GIT_COMMITTER_DATE &&
+	git checkout -b mode initial &&
+	git update-index --chmod=+x file0 &&
+	git commit -m "update mode" &&
+	git checkout -f master &&
+
 	git config diff.renames false &&
 
 	git show-branch
@@ -192,6 +200,10 @@ diff-tree --pretty side
 diff-tree --pretty -p side
 diff-tree --pretty --patch-with-stat side
 
+diff-tree initial mode
+diff-tree --stat initial mode
+diff-tree --summary initial mode
+
 diff-tree master
 diff-tree -p master
 diff-tree -p -m master

t/t4013/diff.diff-tree_--stat_initial_mode

@@ -0,0 +1,4 @@
+$ git diff-tree --stat initial mode
+ file0 | 0
+ 1 file changed, 0 insertions(+), 0 deletions(-)
+$

t/t4013/diff.diff-tree_--summary_initial_mode

@@ -0,0 +1,3 @@
+$ git diff-tree --summary initial mode
+ mode change 100644 => 100755 file0
+$

t/t4013/diff.diff-tree_initial_mode

@@ -0,0 +1,3 @@
+$ git diff-tree initial mode
+:100644 100755 01e79c32a8c99c557f0757da7cb6d65b3414466d 01e79c32a8c99c557f0757da7cb6d65b3414466d M	file0
+$

t/t4013/diff.log_--decorate=full_--all

@@ -1,4 +1,10 @@
 $ git log --decorate=full --all
+commit b7e0bc69303b488b47deca799a7d723971dfa6cd (refs/heads/mode)
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:06:00 2006 +0000
+
+    update mode
+
 commit cd4e72fd96faed3f0ba949dc42967430374e2290 (refs/heads/rearrange)
 Author: A U Thor <author@example.com>
 Date:   Mon Jun 26 00:06:00 2006 +0000

t/t4013/diff.log_--decorate_--all

@@ -1,4 +1,10 @@
 $ git log --decorate --all
+commit b7e0bc69303b488b47deca799a7d723971dfa6cd (mode)
+Author: A U Thor <author@example.com>
+Date:   Mon Jun 26 00:06:00 2006 +0000
+
+    update mode
+
 commit cd4e72fd96faed3f0ba949dc42967430374e2290 (rearrange)
 Author: A U Thor <author@example.com>
 Date:   Mon Jun 26 00:06:00 2006 +0000