git-blame: --show-name (and -f)

The new option makes the command's native output format show the
filename even when there were no renames in its history, to make
it simpler for Porcelains to parse its output.

Signed-off-by: Junio C Hamano <junkio@cox.net>

blame.c

@@ -752,7 +752,7 @@ int main(int argc, const char **argv)
 	const char *buf;
 	int max_digits;
 	int longest_file, longest_author;
-	int found_rename;
+	int show_name = 0;
 
 	const char *prefix = setup_git_directory();
 	git_config(git_default_config);
@@ -786,6 +786,11 @@ int main(int argc, const char **argv)
 				}
 				usage(blame_usage);
 			}
+			if (!strcmp(argv[i], "-f") ||
+			    !strcmp(argv[i], "--show-name")) {
+				show_name = 1;
+				continue;
+			}
 			if (!strcmp(argv[i], "--")) {
 				options = 0;
 				continue;
@@ -853,16 +858,15 @@ int main(int argc, const char **argv)
 
 	longest_file = 0;
 	longest_author = 0;
-	found_rename = 0;
 	for (i = 0; i < num_blame_lines; i++) {
 		struct commit *c = blame_lines[i];
 		struct util_info *u;
 		if (!c)
 			c = initial;
 		u = c->util;
 
-		if (!found_rename && strcmp(filename, u->pathname))
-			found_rename = 1;
+		if (!show_name && strcmp(filename, u->pathname))
+			show_name = 1;
 		if (longest_file < strlen(u->pathname))
 			longest_file = strlen(u->pathname);
 		get_commit_info(c, &ci);
@@ -886,7 +890,7 @@ int main(int argc, const char **argv)
 			       i+1);
 		}
 		else {
-			if (found_rename)
+			if (show_name)
 				printf(" %-*.*s", longest_file, longest_file,
 				       u->pathname);
 			printf(" (%-*.*s %10s %*d) ",