revision.c: add show_object_with_name() helper function

There are two copies of traverse_commit_list callback that show the object
name followed by pathname the object was found, to produce output similar
to "rev-list --objects".

Unify them.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/rev-list.c

@@ -176,21 +176,8 @@ static void finish_object(struct object *obj, const struct name_path *path, cons
 
 static void show_object(struct object *obj, const struct name_path *path, const char *component)
 {
-	char *name = path_name(path, component);
-	/* An object with name "foo\n0000000..." can be used to
-	 * confuse downstream "git pack-objects" very badly.
-	 */
-	const char *ep = strchr(name, '\n');
-
 	finish_object(obj, path, component);
-	if (ep) {
-		printf("%s %.*s\n", sha1_to_hex(obj->sha1),
-		       (int) (ep - name),
-		       name);
-	}
-	else
-		printf("%s %s\n", sha1_to_hex(obj->sha1), name);
-	free(name);
+	show_object_with_name(stdout, obj, path, component);
 }
 
 static void show_edge(struct commit *commit)

revision.c

@@ -40,6 +40,25 @@ char *path_name(const struct name_path *path, const char *name)
 	return n;
 }
 
+void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
+{
+	char *name = path_name(path, component);
+	const char *ep = strchr(name, '\n');
+
+	/*
+	 * An object with name "foo\n0000000..." can be used to
+	 * confuse downstream "git pack-objects" very badly.
+	 */
+	if (ep) {
+		fprintf(out, "%s %.*s\n", sha1_to_hex(obj->sha1),
+			(int) (ep - name),
+			name);
+	}
+	else
+		fprintf(out, "%s %s\n", sha1_to_hex(obj->sha1), name);
+	free(name);
+}
+
 void add_object(struct object *obj,
 		struct object_array *p,
 		struct name_path *path,

revision.h

@@ -185,6 +185,8 @@ struct name_path {
 
 char *path_name(const struct name_path *path, const char *name);
 
+extern void show_object_with_name(FILE *, struct object *, const struct name_path *, const char *);
+
 extern void add_object(struct object *obj,
 		       struct object_array *p,
 		       struct name_path *path,

upload-pack.c

@@ -85,20 +85,7 @@ static void show_commit(struct commit *commit, void *data)
 
 static void show_object(struct object *obj, const struct name_path *path, const char *component)
 {
-	/* An object with name "foo\n0000000..." can be used to
-	 * confuse downstream git-pack-objects very badly.
-	 */
-	const char *name = path_name(path, component);
-	const char *ep = strchr(name, '\n');
-	if (ep) {
-		fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(obj->sha1),
-		       (int) (ep - name),
-		       name);
-	}
-	else
-		fprintf(pack_pipe, "%s %s\n",
-				sha1_to_hex(obj->sha1), name);
-	free((char *)name);
+	show_object_with_name(pack_pipe, obj, path, component);
 }
 
 static void show_edge(struct commit *commit)