Merge branch 'en/status-multiple-renames-to-the-same-target-fix'

The code in "git status" sometimes hit an assertion failure.  This
was caused by a structure that was reused without cleaning the data
used for the first run, which has been corrected.

* en/status-multiple-renames-to-the-same-target-fix:
  commit: fix erroneous BUG, 'multiple renames on the same target? how?'

Author: gitster

builtin/commit.c

@@ -874,6 +874,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		s->use_color = 0;
 		commitable = run_status(s->fp, index_file, prefix, 1, s);
 		s->use_color = saved_color_setting;
+		string_list_clear(&s->change, 1);
 	} else {
 		struct object_id oid;
 		const char *parent = "HEAD";

t/t7500-commit.sh

@@ -359,4 +359,27 @@ test_expect_success 'new line found before status message in commit template' '
 	test_i18ncmp expected-template editor-input
 '
 
+test_expect_success 'setup empty commit with unstaged rename and copy' '
+	test_create_repo unstaged_rename_and_copy &&
+	(
+		cd unstaged_rename_and_copy &&
+
+		echo content >orig &&
+		git add orig &&
+		test_commit orig &&
+
+		cp orig new_copy &&
+		mv orig new_rename &&
+		git add -N new_copy new_rename
+	)
+'
+
+test_expect_success 'check commit with unstaged rename and copy' '
+	(
+		cd unstaged_rename_and_copy &&
+
+		test_must_fail git -c diff.renames=copy commit
+	)
+'
+
 test_done