diff --git a/builtin-diff.c b/builtin-diff.c
index 1b615991e1..55fb84c730 100644
--- a/builtin-diff.c
+++ b/builtin-diff.c
@@ -176,18 +176,6 @@ static int builtin_diff_combined(struct rev_info *revs,
 	return 0;
 }
 
-void add_head(struct rev_info *revs)
-{
-	unsigned char sha1[20];
-	struct object *obj;
-	if (get_sha1("HEAD", sha1))
-		return;
-	obj = parse_object(sha1);
-	if (!obj)
-		return;
-	add_pending_object(revs, obj, "HEAD");
-}
-
 static void refresh_index_quietly(void)
 {
 	struct lock_file *lock_file;
@@ -272,7 +260,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 			if (!strcmp(arg, "--"))
 				break;
 			else if (!strcmp(arg, "--cached")) {
-				add_head(&rev);
+				add_head_to_pending(&rev);
 				if (!rev.pending.nr)
 					die("No HEAD commit to compare with (yet)");
 				break;
diff --git a/builtin-log.c b/builtin-log.c
index e1f1cf6714..d375c9dbf9 100644
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -18,9 +18,6 @@
 static int default_show_root = 1;
 static const char *fmt_patch_subject_prefix = "PATCH";
 
-/* this is in builtin-diff.c */
-void add_head(struct rev_info *revs);
-
 static void add_name_decoration(const char *prefix, const char *name, struct object *obj)
 {
 	int plen = strlen(prefix);
@@ -746,7 +743,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			 * does not have.
 			 */
 			rev.pending.objects[0].item->flags |= UNINTERESTING;
-			add_head(&rev);
+			add_head_to_pending(&rev);
 		}
 		/*
 		 * Otherwise, it is "format-patch -22 HEAD", and/or
diff --git a/builtin-shortlog.c b/builtin-shortlog.c
index 90666cbd78..3d8d7094ab 100644
--- a/builtin-shortlog.c
+++ b/builtin-shortlog.c
@@ -249,9 +249,10 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
 
 	read_mailmap(&mailmap, ".mailmap", &common_repo_prefix);
 
+	/* assume HEAD if from a tty */
+	if (!rev.pending.nr && isatty(0))
+		add_head_to_pending(&rev);
 	if (rev.pending.nr == 0) {
-		if (isatty(0))
-			fprintf(stderr, "(reading log to summarize from standard input)\n");
 		read_from_stdin(&list);
 	}
 	else
diff --git a/revision.c b/revision.c
index 2a59035192..7e2f4f1eb5 100644
--- a/revision.c
+++ b/revision.c
@@ -139,6 +139,18 @@ void add_pending_object(struct rev_info *revs, struct object *obj, const char *n
 	add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 }
 
+void add_head_to_pending(struct rev_info *revs)
+{
+	unsigned char sha1[20];
+	struct object *obj;
+	if (get_sha1("HEAD", sha1))
+		return;
+	obj = parse_object(sha1);
+	if (!obj)
+		return;
+	add_pending_object(revs, obj, "HEAD");
+}
+
 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 {
 	struct object *object;
diff --git a/revision.h b/revision.h
index 992e1e9dd5..8572315954 100644
--- a/revision.h
+++ b/revision.h
@@ -130,6 +130,8 @@ extern void add_object(struct object *obj,
 
 extern void add_pending_object(struct rev_info *revs, struct object *obj, const char *name);
 
+extern void add_head_to_pending(struct rev_info *);
+
 enum commit_action {
 	commit_ignore,
 	commit_show,