6 files changed, 75 insertions, 69 deletions

diff --git a/cgit.c b/cgit.c
index b936a70..3fc90bf 100644
--- a/cgit.c
+++ b/cgit.c
@@ -103,8 +103,7 @@ static void cgit_print_repo_page(struct cacheitem *item)
                 cgit_print_commit(cgit_query_sha1);
                 break;
         case CMD_DIFF:
-                cgit_print_diff(cgit_query_head, cgit_query_sha1, cgit_query_sha2,
-                                cgit_query_path);
+                cgit_print_diff(cgit_query_sha1, cgit_query_sha2);
                 break;
         default:
                 cgit_print_error("Invalid request");
diff --git a/cgit.h b/cgit.h
index c276a24..bd2dd0d 100644
--- a/cgit.h
+++ b/cgit.h
@@ -207,6 +207,8 @@ extern void cgit_log_link(char *name, char *title, char *class, char *head,
                           char *rev, char *path);
 extern void cgit_commit_link(char *name, char *title, char *class, char *head,
                              char *rev);
+extern void cgit_diff_link(char *name, char *title, char *class, char *head,
+                           char *new_rev, char *old_rev, char *path);
 
 extern void cgit_print_error(char *msg);
 extern void cgit_print_date(time_t secs, char *format);
@@ -223,9 +225,8 @@ extern void cgit_print_summary();
 extern void cgit_print_log(const char *tip, int ofs, int cnt, char *grep, char *path, int pager);
 extern void cgit_print_blob(struct cacheitem *item, const char *hex, char *path);
 extern void cgit_print_tree(const char *rev, char *path);
-extern void cgit_print_commit(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_commit(char *hex);
+extern void cgit_print_diff(const char *new_hex, const char *old_hex);
 extern void cgit_print_snapshot(struct cacheitem *item, const char *hex,
                                 const char *format, const char *prefix,
                                 const char *filename);
diff --git a/shared.c b/shared.c
index c7cd8a5..f20fb5c 100644
--- a/shared.c
+++ b/shared.c
@@ -360,7 +360,7 @@ void cgit_diff_tree(const unsigned char *old_sha1,
         opt.format_callback_data = fn;
         diff_setup_done(&opt);
 
-        if (old_sha1)
+        if (old_sha1 && !is_null_sha1(old_sha1))
                 ret = diff_tree_sha1(old_sha1, new_sha1, "", &opt);
         else
                 ret = diff_root_tree_sha1(new_sha1, "", &opt);
diff --git a/ui-commit.c b/ui-commit.c
index d489d7c..2679b59 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -11,6 +11,7 @@
 static int files, slots;
 static int total_adds, total_rems, max_changes;
 static int lines_added, lines_removed;
+static char *curr_rev;
 
 static struct fileinfo {
         char status;
@@ -27,7 +28,6 @@ static struct fileinfo {
 
 void print_fileinfo(struct fileinfo *info)
 {
-        char *query, *query2;
         char *class;
 
         switch (info->status) {
@@ -75,24 +75,12 @@ void print_fileinfo(struct fileinfo *info)
                 html("]</span>");
         }
         htmlf("</td><td class='%s'>", class);
-        query = fmt("id=%s&amp;id2=%s&amp;path=%s", sha1_to_hex(info->old_sha1),
-                    sha1_to_hex(info->new_sha1), info->new_path);
-        html_link_open(cgit_pageurl(cgit_query_repo, "diff", query),
-                       NULL, NULL);
-        if (info->status == DIFF_STATUS_COPIED ||
-            info->status == DIFF_STATUS_RENAMED) {
-                html_txt(info->new_path);
-                htmlf("</a> (%s from ", info->status == DIFF_STATUS_COPIED ?
-                      "copied" : "renamed");
-                query2 = fmt("id=%s", sha1_to_hex(info->old_sha1));
-                html_link_open(cgit_pageurl(cgit_query_repo, "view", query2),
-                               NULL, NULL);
-                html_txt(info->old_path);
-                html("</a>)");
-        } else {
-                html_txt(info->new_path);
-                html("</a>");
-        }
+        cgit_tree_link(info->new_path, NULL, NULL, cgit_query_head, curr_rev,
+                       info->new_path);
+        if (info->status == DIFF_STATUS_COPIED || info->status == DIFF_STATUS_RENAMED)
+                htmlf(" (%s from %s)",
+                      info->status == DIFF_STATUS_COPIED ? "copied" : "renamed",
+                      info->old_path);
         html("</td><td class='right'>");
         htmlf("%d", info->added + info->removed);
         html("</td><td class='graph'>");
@@ -145,19 +133,19 @@ void inspect_filepair(struct diff_filepair *pair)
 }
 
 
-void cgit_print_commit(const char *hex)
+void cgit_print_commit(char *hex)
 {
         struct commit *commit, *parent;
         struct commitinfo *info;
         struct commit_list *p;
         unsigned char sha1[20];
-        char *query;
         char *filename;
         char *tmp;
         int i;
 
         if (!hex)
                 hex = cgit_query_head;
+        curr_rev = hex;
 
         if (get_sha1(hex, sha1)) {
                 cgit_print_error(fmt("Bad object id: %s", hex));
@@ -202,11 +190,10 @@ void cgit_print_commit(const char *hex)
                      "<td colspan='2' class='sha1'>");
                 cgit_commit_link(sha1_to_hex(p->item->object.sha1), NULL, NULL,
                                  cgit_query_head, sha1_to_hex(p->item->object.sha1));
-                html(" (<a href='");
-                query = fmt("id=%s&amp;id2=%s", sha1_to_hex(parent->tree->object.sha1),
-                            sha1_to_hex(commit->tree->object.sha1));
-                html_attr(cgit_pageurl(cgit_query_repo, "diff", query));
-                html("'>diff</a>)</td></tr>");
+                html(" (");
+                cgit_diff_link("diff", NULL, NULL, cgit_query_head, hex,
+                               sha1_to_hex(p->item->object.sha1), NULL);
+                html(")</td></tr>");
         }
         if (cgit_repo->snapshots) {
                 htmlf("<tr><th>download</th><td colspan='2' class='sha1'><a href='");
@@ -233,10 +220,9 @@ void cgit_print_commit(const char *hex)
                 html("<div class='diffstat-summary'>");
                 htmlf("%d files changed, %d insertions, %d deletions (",
                       files, total_adds, total_rems);
-                query = fmt("h=%s", hex);
-                html_link_open(cgit_pageurl(cgit_query_repo, "diff", query), NULL, NULL);
-                html("show diff</a>)");
-                html("</div>");
+                cgit_diff_link("show diff", NULL, NULL, cgit_query_head, hex,
+                               NULL, NULL);
+                html(")</div>");
         }
         cgit_free_commitinfo(info);
 }
diff --git a/ui-diff.c b/ui-diff.c
index 5c864d9..a76a234 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -89,54 +89,52 @@ static void filepair_cb(struct diff_filepair *pair)
                 cgit_print_error("Error running diff");
 }
 
-void cgit_print_diff(const char *head, const char *old_hex, const char *new_hex, char *path)
+void cgit_print_diff(const char *new_rev, const char *old_rev)
 {
         unsigned char sha1[20], sha2[20];
         enum object_type type;
         unsigned long size;
-        struct commit *commit;
+        struct commit *commit, *commit2;
 
-        html("<table class='diff'>");
-        html("<tr><td>");
-
-        if (head && !old_hex && !new_hex) {
-                get_sha1(head, sha1);
-                commit = lookup_commit_reference(sha1);
-                if (commit && !parse_commit(commit))
-                        cgit_diff_commit(commit, filepair_cb);
-                else
-                        cgit_print_error(fmt("Bad commit: %s", head));
-                html("</td></tr>");
-                html("</table>");
+        if (!new_rev)
+                new_rev = cgit_query_head;
+        get_sha1(new_rev, sha1);
+        type = sha1_object_info(sha1, &size);
+        if (type == OBJ_BAD) {
+                cgit_print_error(fmt("Bad object name: %s", new_rev));
+                return;
+        }
+        if (type != OBJ_COMMIT) {
+                cgit_print_error(fmt("Unhandled object type: %s",
+                                     typename(type)));
                 return;
         }
 
-        get_sha1(old_hex, sha1);
-        get_sha1(new_hex, sha2);
+        commit = lookup_commit_reference(sha1);
+        if (!commit || parse_commit(commit))
+                cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(sha1)));
 
-        type = sha1_object_info(sha1, &size);
-        if (type == OBJ_BAD) {
+        if (old_rev)
+                get_sha1(old_rev, sha2);
+        else if (commit->parents && commit->parents->item)
+                hashcpy(sha2, commit->parents->item->object.sha1);
+        else
+                hashclr(sha2);
+
+        if (!is_null_sha1(sha2)) {
                 type = sha1_object_info(sha2, &size);
                 if (type == OBJ_BAD) {
-                        cgit_print_error(fmt("Bad object names: %s, %s", old_hex, new_hex));
+                        cgit_print_error(fmt("Bad object name: %s", sha1_to_hex(sha2)));
                         return;
                 }
+                commit2 = lookup_commit_reference(sha2);
+                if (!commit2 || parse_commit(commit2))
+                        cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(sha2)));
         }
 
-        switch(type) {
-        case OBJ_BLOB:
-                header(sha1, path, 0644, sha2, path, 0644);
-                if (cgit_diff_files(sha1, sha2, print_line))
-                        cgit_print_error("Error running diff");
-                break;
-        case OBJ_TREE:
-                cgit_diff_tree(sha1, sha2, filepair_cb);
-                break;
-        default:
-                cgit_print_error(fmt("Unhandled object type: %s",
-                                     typename(type)));
-                break;
-        }
+        html("<table class='diff'>");
+        html("<tr><td>");
+        cgit_diff_tree(sha2, sha1, filepair_cb);
         html("</td></tr>");
         html("</table>");
 }
diff --git a/ui-shared.c b/ui-shared.c
index 71c899a..15d8254 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -176,6 +176,28 @@ void cgit_commit_link(char *name, char *title, char *class, char *head,
         reporevlink("commit", name, title, class, head, rev, NULL);
 }
 
+void cgit_diff_link(char *name, char *title, char *class, char *head,
+                    char *new_rev, char *old_rev, char *path)
+{
+        char *delim;
+
+        delim = repolink(title, class, "diff", head, path);
+        if (new_rev && strcmp(new_rev, cgit_query_head)) {
+                html(delim);
+                html("id=");
+                html_attr(new_rev);
+                delim = "&amp;";
+        }
+        if (old_rev) {
+                html(delim);
+                html("id2=");
+                html_attr(old_rev);
+        }
+        html("'>");
+        html_txt(name);
+        html("</a>");
+}
+
 void cgit_print_date(time_t secs, char *format)
 {
         char buf[64];