[PATCH] git-merge-cache -q doesn't complain about failing merge program

git-merge-cache reporting failed merge program is undesirable for
Cogito, since it emits its own more appropriate error message in that
case. However, I want to show other possible git-merge-cache error
messages. So -q will just silence this particular error.

Signed-off-by: Petr Baudis <pasky@ucw.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-merge-cache.txt

@@ -9,7 +9,7 @@ git-merge-cache - Runs a merge for files needing merging
 
 SYNOPSIS
 --------
-'git-merge-cache' [-o] <merge-program> (-a | -- | <file>\*) 
+'git-merge-cache' [-o] [-q] <merge-program> (-a | -- | <file>\*) 
 
 DESCRIPTION
 -----------
@@ -32,6 +32,11 @@ OPTIONS
 	returned errors, and only return the error code after all the
 	merges are over.
 
+-q::
+	Do not complain about failed merge program (the merge program
+	failure usually indicates conflicts during merge). This is for
+	porcelains which might want to emit custom messages.
+
 If "git-merge-cache" is called with multiple <file>s (or -a) then it
 processes them in turn only stopping if merge returns a non-zero exit
 code.
@@ -40,7 +45,7 @@ Typically this is run with the a script calling the merge command from
 the RCS package.
 
 A sample script called "git-merge-one-file-script" is included in the
-ditribution.
+distribution.
 
 ALERT ALERT ALERT! The git "merge object order" is different from the
 RCS "merge" program merge object order. In the above ordering, the

merge-cache.c

@@ -5,7 +5,7 @@
 
 static const char *pgm = NULL;
 static const char *arguments[8];
-static int one_shot;
+static int one_shot, quiet;
 static int err;
 
 static void run_program(void)
@@ -27,10 +27,13 @@ static void run_program(void)
 		die("unable to execute '%s'", pgm);
 	}
 	if (waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) || WEXITSTATUS(status)) {
-		if (one_shot)
+		if (one_shot) {
 			err++;
-		else
-			die("merge program failed");
+		} else {
+			if (quiet)
+				die("merge program failed");
+			exit(1);
+		}
 	}
 }
 
@@ -97,15 +100,19 @@ int main(int argc, char **argv)
 	int i, force_file = 0;
 
 	if (argc < 3)
-		usage("git-merge-cache [-o] <merge-program> (-a | <filename>*)");
+		usage("git-merge-cache [-o] [-q] <merge-program> (-a | <filename>*)");
 
 	read_cache();
 
 	i = 1;
-	if (!strcmp(argv[1], "-o")) {
+	if (!strcmp(argv[i], "-o")) {
 		one_shot = 1;
 		i++;
 	}
+	if (!strcmp(argv[i], "-q")) {
+		quiet = 1;
+		i++;
+	}
 	pgm = argv[i++];
 	for (; i < argc; i++) {
 		char *arg = argv[i];
@@ -122,7 +129,7 @@ int main(int argc, char **argv)
 		}
 		merge_file(arg);
 	}
-	if (err)
+	if (err && quiet)
 		die("merge program failed");
-	return 0;
+	return err;
 }