2 files changed, 50 insertions, 2 deletions

diff --git a/cgit.h b/cgit.h
index b7f8827..24b02d7 100644
--- a/cgit.h
+++ b/cgit.h
@@ -19,6 +19,7 @@
 
 
 typedef void (*configfn)(const char *name, const char *value);
+typedef void (*filepair_fn)(struct diff_filepair *pair);
 
 struct cacheitem {
         char *name;
@@ -116,6 +117,10 @@ extern int chk_positive(int result, char *msg);
 extern int hextoint(char c);
 
 extern void *cgit_free_commitinfo(struct commitinfo *info);
+extern void cgit_diff_tree(const unsigned char *old_sha1,
+                           const unsigned char *new_sha1,
+                           filepair_fn fn);
+extern void cgit_diff_commit(struct commit *commit, filepair_fn fn);
 
 extern char *fmt(const char *format,...);
 
diff --git a/shared.c b/shared.c
index 19d2df0..f8a17b6 100644
--- a/shared.c
+++ b/shared.c
@@ -74,8 +74,8 @@ struct repoinfo *add_repo(const char *url)
                         cgit_repolist.length = 8;
                 else
                         cgit_repolist.length *= 2;
-                cgit_repolist.repos = xrealloc(cgit_repolist.repos, 
-                                               cgit_repolist.length * 
+                cgit_repolist.repos = xrealloc(cgit_repolist.repos,
+                                               cgit_repolist.length *
                                                sizeof(struct repoinfo));
         }
 
@@ -195,3 +195,46 @@ int hextoint(char c)
                 return -1;
 }
 
+void cgit_diff_tree_cb(struct diff_queue_struct *q,
+                       struct diff_options *options, void *data)
+{
+        int i;
+
+        for (i = 0; i < q->nr; i++) {
+                if (q->queue[i]->status == 'U')
+                        continue;
+                ((filepair_fn)data)(q->queue[i]);
+        }
+}
+
+void cgit_diff_tree(const unsigned char *old_sha1,
+                    const unsigned char *new_sha1,
+                    filepair_fn fn)
+{
+        struct diff_options opt;
+        int ret;
+
+        diff_setup(&opt);
+        opt.output_format = DIFF_FORMAT_CALLBACK;
+        opt.detect_rename = 1;
+        opt.recursive = 1;
+        opt.format_callback = cgit_diff_tree_cb;
+        opt.format_callback_data = fn;
+        diff_setup_done(&opt);
+
+        if (old_sha1)
+                ret = diff_tree_sha1(old_sha1, new_sha1, "", &opt);
+        else
+                ret = diff_root_tree_sha1(new_sha1, "", &opt);
+        diffcore_std(&opt);
+        diff_flush(&opt);
+}
+
+void cgit_diff_commit(struct commit *commit, filepair_fn fn)
+{
+        unsigned char *old_sha1 = NULL;
+
+        if (commit->parents)
+                old_sha1 = commit->parents->item->object.sha1;
+        cgit_diff_tree(old_sha1, commit->object.sha1, fn);
+}