Export launch_editor() and make it accept ':' as a no-op editor.

Signed-off-by: NKristian Høgsberg <krh@redhat.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin-tag.c

@@ -17,7 +17,7 @@ static const char builtin_tag_usage[] =
 
 static char signingkey[1000];
 
-static void launch_editor(const char *path, struct strbuf *buffer)
+void launch_editor(const char *path, struct strbuf *buffer)
 {
 	const char *editor, *terminal;
 	struct child_process child;
@@ -42,6 +42,9 @@ static void launch_editor(const char *path, struct strbuf *buffer)
 	if (!editor)
 		editor = "vi";
 
+	if (!strcmp(editor, ":"))
+		return;
+
 	memset(&child, 0, sizeof(child));
 	child.argv = args;
 	args[0] = editor;

strbuf.h

@@ -117,5 +117,6 @@ extern int strbuf_read_file(struct strbuf *sb, const char *path, size_t hint);
 extern int strbuf_getline(struct strbuf *, FILE *, int);
 
 extern void stripspace(struct strbuf *buf, int skip_comments);
+extern void launch_editor(const char *path, struct strbuf *buffer);
 
 #endif /* STRBUF_H */