commit - 26ed57b23d183a3ea7aa46e7509f935e35e7554e
commit + 11528a829855823153f2aaa9438bdf400a2995d7
blob - c8a1143bff915c1c1c59d727dfcef953b0a84956
blob + a4134598a23ddc10569bfd34fb1e4250e3385913
--- got/got.c
+++ got/got.c
@@ -519,90 +519,8 @@ cmd_log(int argc, char *argv[])
 	free(id);
 	got_repo_close(repo);
 	return error;
-}
-
-static const struct got_error *
-diff_blobs(struct got_object *obj1, struct got_object *obj2,
-    struct got_repository *repo)
-{
-	const struct got_error *err;
-	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
-
-	err = got_object_blob_open(&blob1, repo, obj1, 8192);
-	if (err)
-		goto done;
-	err = got_object_blob_open(&blob2, repo, obj2, 8192);
-	if (err)
-		goto done;
-
-	err = got_diff_blob(blob1, blob2, NULL, NULL, stdout);
-done:
-	if (blob1)
-		got_object_blob_close(blob1);
-	if (blob2)
-		got_object_blob_close(blob2);
-	return err;
-}
-
-static const struct got_error *
-diff_trees(struct got_object *obj1, struct got_object *obj2,
-    struct got_repository *repo)
-{
-	const struct got_error *err;
-	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
-
-	err = got_object_tree_open(&tree1, repo, obj1);
-	if (err)
-		goto done;
-	err = got_object_tree_open(&tree2, repo, obj2);
-	if (err)
-		goto done;
-
-	err = got_diff_tree(tree1, tree2, repo, stdout);
-done:
-	if (tree1)
-		got_object_tree_close(tree1);
-	if (tree2)
-		got_object_tree_close(tree2);
-	return err;
 }
 
-static const struct got_error *
-diff_commits(struct got_object *obj1, struct got_object *obj2,
-    struct got_repository *repo)
-{
-	const struct got_error *err;
-	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
-	struct got_object *tree_obj1  = NULL, *tree_obj2 = NULL;
-
-	err = got_object_commit_open(&commit1, repo, obj1);
-	if (err)
-		goto done;
-	err = got_object_commit_open(&commit2, repo, obj2);
-	if (err)
-		goto done;
-
-	err = got_object_open(&tree_obj1, repo, commit1->tree_id);
-	if (err)
-		goto done;
-	err = got_object_open(&tree_obj2, repo, commit2->tree_id);
-	if (err)
-		goto done;
-
-	err = diff_trees(tree_obj1, tree_obj2, repo);
-done:
-	if (tree_obj1)
-		got_object_close(tree_obj1);
-	if (tree_obj2)
-		got_object_close(tree_obj2);
-	if (commit1)
-		got_object_commit_close(commit1);
-	if (commit2)
-		got_object_commit_close(commit2);
-	return err;
-
-}
-
 __dead void
 usage_diff(void)
 {
@@ -685,13 +603,13 @@ cmd_diff(int argc, char *argv[])
 
 	switch (got_object_get_type(obj1)) {
 	case GOT_OBJ_TYPE_BLOB:
-		error = diff_blobs(obj1, obj2, repo);
+		error = got_diff_objects_as_blobs(obj1, obj2, repo, stdout);
 		break;
 	case GOT_OBJ_TYPE_TREE:
-		error = diff_trees(obj1, obj2, repo);
+		error = got_diff_objects_as_trees(obj1, obj2, repo, stdout);
 		break;
 	case GOT_OBJ_TYPE_COMMIT:
-		error = diff_commits(obj1, obj2, repo);
+		error = got_diff_objects_as_commits(obj1, obj2, repo, stdout);
 		break;
 	default:
 		error = got_error(GOT_ERR_OBJ_TYPE);
blob - 4673b9c5bf89bc6b2ed60ed83a5a1ee337865617
blob + 0f04bd8dc24610ab8b6aa4a71934829503df5230
--- include/got_diff.h
+++ include/got_diff.h
@@ -29,3 +29,24 @@ const struct got_error *got_diff_blob(struct got_blob_
  */
 const struct got_error *got_diff_tree(struct got_tree_object *,
     struct got_tree_object *, struct got_repository *, FILE *);
+
+/*
+ * Diff two objects, assuming both objects are blobs.
+ * Write unified diff text to the provided output FILE.
+ */
+const struct got_error *got_diff_objects_as_blobs(struct got_object *,
+    struct got_object *, struct got_repository *, FILE *);
+
+/*
+ * Diff two objects, assuming both objects are trees.
+ * Write unified diff text to the provided output FILE.
+ */
+const struct got_error *got_diff_objects_as_trees(struct got_object *,
+    struct got_object *, struct got_repository *, FILE *);
+
+/*
+ * Diff two objects, assuming both objects are commits.
+ * Write unified diff text to the provided output FILE.
+ */
+const struct got_error *got_diff_objects_as_commits(struct got_object *,
+    struct got_object *, struct got_repository *, FILE *);
blob - 2edc9fdd16423ddcf986299d5139b69fdf772c6d
blob + 85c538615c4936d03916032ae8518959958e942f
--- lib/diff.c
+++ lib/diff.c
@@ -436,6 +436,87 @@ got_diff_tree(struct got_tree_object *tree1, struct go
 		if (te2)
 			te2 = SIMPLEQ_NEXT(te2, entry);
 	} while (te1 || te2);
+
+	return err;
+}
+
+const struct got_error *
+got_diff_objects_as_blobs(struct got_object *obj1, struct got_object *obj2,
+    struct got_repository *repo, FILE *outfile)
+{
+	const struct got_error *err;
+	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
+
+	err = got_object_blob_open(&blob1, repo, obj1, 8192);
+	if (err)
+		goto done;
+	err = got_object_blob_open(&blob2, repo, obj2, 8192);
+	if (err)
+		goto done;
 
+	err = got_diff_blob(blob1, blob2, NULL, NULL, outfile);
+done:
+	if (blob1)
+		got_object_blob_close(blob1);
+	if (blob2)
+		got_object_blob_close(blob2);
 	return err;
 }
+
+const struct got_error *
+got_diff_objects_as_trees(struct got_object *obj1, struct got_object *obj2,
+    struct got_repository *repo, FILE *outfile)
+{
+	const struct got_error *err;
+	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
+
+	err = got_object_tree_open(&tree1, repo, obj1);
+	if (err)
+		goto done;
+	err = got_object_tree_open(&tree2, repo, obj2);
+	if (err)
+		goto done;
+
+	err = got_diff_tree(tree1, tree2, repo, outfile);
+done:
+	if (tree1)
+		got_object_tree_close(tree1);
+	if (tree2)
+		got_object_tree_close(tree2);
+	return err;
+}
+
+const struct got_error *
+got_diff_objects_as_commits(struct got_object *obj1, struct got_object *obj2,
+    struct got_repository *repo, FILE *outfile)
+{
+	const struct got_error *err;
+	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
+	struct got_object *tree_obj1  = NULL, *tree_obj2 = NULL;
+
+	err = got_object_commit_open(&commit1, repo, obj1);
+	if (err)
+		goto done;
+	err = got_object_commit_open(&commit2, repo, obj2);
+	if (err)
+		goto done;
+
+	err = got_object_open(&tree_obj1, repo, commit1->tree_id);
+	if (err)
+		goto done;
+	err = got_object_open(&tree_obj2, repo, commit2->tree_id);
+	if (err)
+		goto done;
+
+	err = got_diff_objects_as_trees(tree_obj1, tree_obj2, repo, outfile);
+done:
+	if (tree_obj1)
+		got_object_close(tree_obj1);
+	if (tree_obj2)
+		got_object_close(tree_obj2);
+	if (commit1)
+		got_object_commit_close(commit1);
+	if (commit2)
+		got_object_commit_close(commit2);
+	return err;
+}
blob - beae1ba444da519f2b75a4992c9b4d1316a2775c
blob + 1eeab3c01b4b597a967bbbbd27de4658259cedac
--- tog/tog.c
+++ tog/tog.c
@@ -776,90 +776,8 @@ usage_diff(void)
 	fprintf(stderr, "usage: %s diff [repository-path] object1 object2\n",
 	    getprogname());
 	exit(1);
-}
-
-static const struct got_error *
-diff_blobs(FILE *outfile, struct got_object *obj1, struct got_object *obj2,
-    struct got_repository *repo)
-{
-	const struct got_error *err;
-	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
-
-	err = got_object_blob_open(&blob1, repo, obj1, 8192);
-	if (err)
-		goto done;
-	err = got_object_blob_open(&blob2, repo, obj2, 8192);
-	if (err)
-		goto done;
-
-	err = got_diff_blob(blob1, blob2, NULL, NULL, outfile);
-done:
-	if (blob1)
-		got_object_blob_close(blob1);
-	if (blob2)
-		got_object_blob_close(blob2);
-	return err;
-}
-
-static const struct got_error *
-diff_trees(FILE *outfile, struct got_object *obj1, struct got_object *obj2,
-    struct got_repository *repo)
-{
-	const struct got_error *err;
-	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
-
-	err = got_object_tree_open(&tree1, repo, obj1);
-	if (err)
-		goto done;
-	err = got_object_tree_open(&tree2, repo, obj2);
-	if (err)
-		goto done;
-
-	err = got_diff_tree(tree1, tree2, repo, outfile);
-done:
-	if (tree1)
-		got_object_tree_close(tree1);
-	if (tree2)
-		got_object_tree_close(tree2);
-	return err;
 }
 
-static const struct got_error *
-diff_commits(FILE *outfile, struct got_object *obj1, struct got_object *obj2,
-    struct got_repository *repo)
-{
-	const struct got_error *err;
-	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
-	struct got_object *tree_obj1  = NULL, *tree_obj2 = NULL;
-
-	err = got_object_commit_open(&commit1, repo, obj1);
-	if (err)
-		goto done;
-	err = got_object_commit_open(&commit2, repo, obj2);
-	if (err)
-		goto done;
-
-	err = got_object_open(&tree_obj1, repo, commit1->tree_id);
-	if (err)
-		goto done;
-	err = got_object_open(&tree_obj2, repo, commit2->tree_id);
-	if (err)
-		goto done;
-
-	err = diff_trees(outfile, tree_obj1, tree_obj2, repo);
-done:
-	if (tree_obj1)
-		got_object_close(tree_obj1);
-	if (tree_obj2)
-		got_object_close(tree_obj2);
-	if (commit1)
-		got_object_commit_close(commit1);
-	if (commit2)
-		got_object_commit_close(commit2);
-	return err;
-
-}
-
 const struct got_error *
 draw_diff(FILE *f, int *first_displayed_line, int *last_displayed_line,
     int *eof, int max_lines)
@@ -920,13 +838,13 @@ show_diff_view(struct got_object *obj1, struct got_obj
 
 	switch (got_object_get_type(obj1)) {
 	case GOT_OBJ_TYPE_BLOB:
-		err = diff_blobs(f, obj1, obj2, repo);
+		err = got_diff_objects_as_blobs(obj1, obj2, repo, f);
 		break;
 	case GOT_OBJ_TYPE_TREE:
-		err = diff_trees(f, obj1, obj2, repo);
+		err = got_diff_objects_as_trees(obj1, obj2, repo, f);
 		break;
 	case GOT_OBJ_TYPE_COMMIT:
-		err = diff_commits(f, obj1, obj2, repo);
+		err = got_diff_objects_as_commits(obj1, obj2, repo, f);
 		break;
 	default:
 		return got_error(GOT_ERR_OBJ_TYPE);