3 files changed, 21 insertions, 7 deletions

diff --git a/cgit.c b/cgit.c
index 9b4815d..3e7e595 100644
--- a/cgit.c
+++ b/cgit.c
@@ -117,13 +117,14 @@ static void cgit_print_repo_page(struct cacheitem *item)
 		cgit_print_tree(cgit_query_head, cgit_query_sha1, cgit_query_path);
 	} else if (!strcmp(cgit_query_page, "commit")) {
 		cgit_print_commit(cgit_query_head);
 	} else if (!strcmp(cgit_query_page, "view")) {
 		cgit_print_view(cgit_query_sha1, cgit_query_path);
 	} else if (!strcmp(cgit_query_page, "diff")) {
-		cgit_print_diff(cgit_query_sha1, cgit_query_sha2, cgit_query_path);
+		cgit_print_diff(cgit_query_head, cgit_query_sha1, cgit_query_sha2,
+				cgit_query_path);
 	} else {
 		cgit_print_error("Invalid request");
 	}
 	cgit_print_docend();
 }
 
diff --git a/cgit.h b/cgit.h
index ac710a6..764225d 100644
--- a/cgit.h
+++ b/cgit.h
@@ -154,31 +154,32 @@ extern int cache_lock(struct cacheitem *item);
 extern int cache_unlock(struct cacheitem *item);
 extern int cache_cancel_lock(struct cacheitem *item);
 extern int cache_exist(struct cacheitem *item);
 extern int cache_expired(struct cacheitem *item);
 
 extern char *cgit_repourl(const char *reponame);
-extern char *cgit_pageurl(const char *reponame, const char *pagename, 
+extern char *cgit_pageurl(const char *reponame, const char *pagename,
 			  const char *query);
 
 extern void cgit_print_error(char *msg);
 extern void cgit_print_date(unsigned long secs);
 extern void cgit_print_docstart(char *title, struct cacheitem *item);
 extern void cgit_print_docend();
 extern void cgit_print_pageheader(char *title, int show_search);
-extern void cgit_print_snapshot_start(const char *mimetype, 
-				      const char *filename, 
+extern void cgit_print_snapshot_start(const char *mimetype,
+				      const char *filename,
 				      struct cacheitem *item);
 
 extern void cgit_print_repolist(struct cacheitem *item);
 extern void cgit_print_summary();
 extern void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *path);
 extern void cgit_print_view(const char *hex, char *path);
 extern void cgit_print_blob(struct cacheitem *item, const char *hex, char *path);
 extern void cgit_print_tree(const char *rev, const char *hex, char *path);
 extern void cgit_print_commit(const char *hex);
-extern void cgit_print_diff(const char *old_hex, const char *new_hex, char *path);
-extern void cgit_print_snapshot(struct cacheitem *item, const char *hex, 
+extern void cgit_print_diff(const char *head, const char *old_hex, const char *new_hex,
+			    char *path);
+extern void cgit_print_snapshot(struct cacheitem *item, const char *hex,
 				const char *format, const char *prefix,
 				const char *filename);
 
 #endif /* CGIT_H */
diff --git a/ui-diff.c b/ui-diff.c
index 999b6f3..afe1c90 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -63,17 +63,29 @@ static void filepair_cb(struct diff_filepair *pair)
 	       pair->two->sha1, pair->two->path);
 	if (cgit_diff_files(pair->one->sha1, pair->two->sha1, print_line))
 		cgit_print_error("Error running diff");
 	html("</tr></td>");
 }
 
-void cgit_print_diff(const char *old_hex, const char *new_hex, char *path)
+void cgit_print_diff(const char *head, const char *old_hex, const char *new_hex, char *path)
 {
 	unsigned char sha1[20], sha2[20];
 	enum object_type type;
 	unsigned long size;
+	struct commit *commit;
+
+	if (head && !old_hex && !new_hex) {
+		get_sha1(head, sha1);
+		commit = lookup_commit_reference(sha1);
+		if (commit && !parse_commit(commit)) {
+			html("<table class='diff'>");
+			cgit_diff_commit(commit, filepair_cb);
+			html("</td></tr></table>");
+		}
+		return;
+	}
 
 	get_sha1(old_hex, sha1);
 	get_sha1(new_hex, sha2);
 
 	type = sha1_object_info(sha1, &size);
 	if (type == OBJ_BAD) {