builtin/stash: factor out revision parsing into a function

We allow several special forms of stash names in this code.  In the
future, we'll want to allow these same forms without parsing a stash
commit, so let's refactor this code out into a function for reuse.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: bk2204

builtin/stash.c

@@ -169,6 +169,25 @@ static void assert_stash_like(struct stash_info *info, const char *revision)
 		die(_("'%s' is not a stash-like commit"), revision);
 }
 
+static int parse_stash_revision(struct strbuf *revision, const char *commit, int quiet)
+{
+	strbuf_reset(revision);
+	if (!commit) {
+		if (!refs_ref_exists(get_main_ref_store(the_repository), ref_stash)) {
+			if (!quiet)
+				fprintf_ln(stderr, _("No stash entries found."));
+			return -1;
+		}
+
+		strbuf_addf(revision, "%s@{0}", ref_stash);
+	} else if (strspn(commit, "0123456789") == strlen(commit)) {
+		strbuf_addf(revision, "%s@{%s}", ref_stash, commit);
+	} else {
+		strbuf_addstr(revision, commit);
+	}
+	return 0;
+}
+
 static int get_stash_info(struct stash_info *info, int argc, const char **argv)
 {
 	int ret;
@@ -196,17 +215,9 @@ static int get_stash_info(struct stash_info *info, int argc, const char **argv)
 	if (argc == 1)
 		commit = argv[0];
 
-	if (!commit) {
-		if (!refs_ref_exists(get_main_ref_store(the_repository), ref_stash)) {
-			fprintf_ln(stderr, _("No stash entries found."));
-			return -1;
-		}
-
-		strbuf_addf(&info->revision, "%s@{0}", ref_stash);
-	} else if (strspn(commit, "0123456789") == strlen(commit)) {
-		strbuf_addf(&info->revision, "%s@{%s}", ref_stash, commit);
-	} else {
-		strbuf_addstr(&info->revision, commit);
+	strbuf_init(&info->revision, 0);
+	if (parse_stash_revision(&info->revision, commit, 0)) {
+		return -1;
 	}
 
 	revision = info->revision.buf;