commit - 8ba9a21905d3eb24a672ceb540ce841273b8d1d3
commit + f78b0693d753895550a74d1b49c4c281cb805d39
blob - bdb83fceee0df5c7676df45f010fcf7eb142e276
blob + 0c42f4e29d86ba34acada6a4617c425b87b55331
--- include/got_object.h
+++ include/got_object.h
@@ -32,6 +32,7 @@ struct got_blob_object {
 	FILE *f;
 	struct got_zstream_buf zb;
 	size_t hdrlen;
+	struct got_object_id id;
 };
 
 struct got_tree_entry {
@@ -75,7 +76,7 @@ struct got_object {
 
 struct got_repository;
 
-const char * got_object_id_str(struct got_object_id *, char *, size_t);
+char * got_object_id_str(struct got_object_id *, char *, size_t);
 const struct got_error *got_object_open(struct got_object **,
     struct got_repository *, struct got_object_id *);
 void got_object_close(struct got_object *);
blob - 2137919d266108f5a8379e4030cd8e1004fbcd3a
blob + f09406d08a92bc51d90d997a6b5c70e139a877d0
--- lib/diff.c
+++ lib/diff.c
@@ -61,6 +61,8 @@ got_diff_blob(struct got_blob_object *blob1, struct go
 	FILE *f1, *f2;
 	char *n1, *n2;
 	size_t len, hdrlen;
+	char hex1[SHA1_DIGEST_STRING_LENGTH];
+	char hex2[SHA1_DIGEST_STRING_LENGTH];
 	int res;
 
 	err = open_tempfile(&f1, &n1);
@@ -102,6 +104,8 @@ got_diff_blob(struct got_blob_object *blob1, struct go
 	memset(&args, 0, sizeof(args));
 
 	args.diff_format = D_UNIFIED;
+	args.label[0] = got_object_id_str(&blob1->id, hex1, sizeof(hex1));
+	args.label[1] = got_object_id_str(&blob2->id, hex2, sizeof(hex2));
 	err = got_diffreg(&res, n1, n2, 0, &args, &ds);
 done:
 	unlink(n1);
blob - 9f51ba2b9750d803ffa4a14f0064cdd5da775840
blob + a000e961e08ed70c7874b041ba122fbffc528181
--- lib/object.c
+++ lib/object.c
@@ -47,7 +47,7 @@
 #define GOT_COMMIT_TAG_AUTHOR		"author "
 #define GOT_COMMIT_TAG_COMMITTER	"committer "
 
-const char *
+char *
 got_object_id_str(struct got_object_id *id, char *buf, size_t size)
 {
 	char *p = buf;
@@ -692,6 +692,7 @@ got_object_blob_open(struct got_blob_object **blob,
 	}
 
 	(*blob)->hdrlen = obj->hdrlen;
+	memcpy(&(*blob)->id.sha1, obj->id.sha1, SHA1_DIGEST_LENGTH);
 
 	free(path);
 	return err;
blob - 926fc74d1f0638380b45f2cbac120b175a884b69
blob + 13ba983f7bbb42075f4dc56c27450e36f0a87a63
--- regress/repository/repository_test.c
+++ regress/repository/repository_test.c
@@ -27,6 +27,7 @@
 #include "got_refs.h"
 #include "got_repository.h"
 #include "got_sha1.h"
+#include "got_diff.h"
 
 #define RUN_TEST(expr, name) \
 	if (!(expr)) { printf("test %s failed", (name)); failure = 1; }
@@ -277,7 +278,7 @@ repo_diff_blob(const char *repo_path)
 		return 0;
 
 	putchar('\n');
-	got_diff_blob(blob1, blob2, repo);
+	got_diff_blob(blob1, blob2, stdout);
 	putchar('\n');
 
 	got_object_blob_close(blob1);