prune: handle --progress/no-progress

And have "git gc" pass no-progress when quiet.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/gc.c

@@ -32,7 +32,7 @@ static const char *prune_expire = "2.weeks.ago";
 static const char *argv_pack_refs[] = {"pack-refs", "--all", "--prune", NULL};
 static const char *argv_reflog[] = {"reflog", "expire", "--all", NULL};
 static const char *argv_repack[MAX_ADD] = {"repack", "-d", "-l", NULL};
-static const char *argv_prune[] = {"prune", "--expire", NULL, NULL};
+static const char *argv_prune[] = {"prune", "--expire", NULL, NULL, NULL};
 static const char *argv_rerere[] = {"rerere", "gc", NULL};
 
 static int gc_config(const char *var, const char *value, void *cb)
@@ -243,6 +243,8 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 
 	if (prune_expire) {
 		argv_prune[2] = prune_expire;
+		if (quiet)
+			argv_prune[3] = "--no-progress";
 		if (run_command_v_opt(argv_prune, RUN_GIT_CMD))
 			return error(FAILED_RUN, argv_prune[0]);
 	}

builtin/prune.c

@@ -15,6 +15,7 @@ static const char * const prune_usage[] = {
 static int show_only;
 static int verbose;
 static unsigned long expire;
+static int show_progress = -1;
 
 static int prune_tmp_object(const char *path, const char *filename)
 {
@@ -125,10 +126,11 @@ static void remove_temporary_files(const char *path)
 int cmd_prune(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
-	struct progress *progress;
+	struct progress *progress = NULL;
 	const struct option options[] = {
 		OPT__DRY_RUN(&show_only, "do not remove, show only"),
 		OPT__VERBOSE(&verbose, "report pruned objects"),
+		OPT_BOOL(0, "progress", &show_progress, "show progress"),
 		OPT_DATE(0, "expire", &expire,
 			 "expire objects older than <time>"),
 		OPT_END()
@@ -154,7 +156,12 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 		else
 			die("unrecognized argument: %s", name);
 	}
-	progress = start_progress_delay("Checking connectivity", 0, 0, 2);
+
+	if (show_progress == -1)
+		show_progress = isatty(2);
+	if (show_progress)
+		progress = start_progress_delay("Checking connectivity", 0, 0, 2);
+
 	mark_reachable_objects(&revs, 1, progress);
 	stop_progress(&progress);
 	prune_object_dir(get_object_directory());