+void *cgit_free_commitinfo(struct commitinfo *info)
+{
+ free(info->author);
+ free(info->author_email);
+ free(info->committer);
+ free(info->committer_email);
+ free(info->subject);
+ free(info);
+ return NULL;
+}
+
+int hextoint(char c)
+{
+ if (c >= 'a' && c <= 'f')
+ return 10 + c - 'a';
+ else if (c >= 'A' && c <= 'F')
+ return 10 + c - 'A';
+ else if (c >= '0' && c <= '9')
+ return c - '0';
+ else
+ return -1;
+}
+
+char *trim_end(const char *str, char c)
+{
+ int len;
+ char *s, *t;
+
+ if (str == NULL)
+ return NULL;
+ t = (char *)str;
+ len = strlen(t);
+ while(len > 0 && t[len - 1] == c)
+ len--;
+
+ if (len == 0)
+ return NULL;
+
+ c = t[len];
+ t[len] = '\0';
+ s = xstrdup(t);
+ t[len] = c;
+ return s;
+}
+
+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]);
+ }
+}
+
+static int load_mmfile(mmfile_t *file, const unsigned char *sha1)
+{
+ enum object_type type;
+
+ if (is_null_sha1(sha1)) {
+ file->ptr = (char *)"";
+ file->size = 0;
+ } else {
+ file->ptr = read_sha1_file(sha1, &type, &file->size);
+ }
+ return 1;
+}
+
+/*
+ * Receive diff-buffers from xdiff and concatenate them as
+ * needed across multiple callbacks.
+ *
+ * This is basically a copy of xdiff-interface.c/xdiff_outf(),
+ * ripped from git and modified to use globals instead of
+ * a special callback-struct.
+ */
+char *diffbuf = NULL;
+int buflen = 0;
+
+int filediff_cb(void *priv, mmbuffer_t *mb, int nbuf)
+{
+ int i;
+
+ for (i = 0; i < nbuf; i++) {
+ if (mb[i].ptr[mb[i].size-1] != '\n') {
+ /* Incomplete line */
+ diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
+ memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
+ buflen += mb[i].size;
+ continue;
+ }
+
+ /* we have a complete line */
+ if (!diffbuf) {
+ ((linediff_fn)priv)(mb[i].ptr, mb[i].size);
+ continue;
+ }
+ diffbuf = xrealloc(diffbuf, buflen + mb[i].size);
+ memcpy(diffbuf + buflen, mb[i].ptr, mb[i].size);
+ ((linediff_fn)priv)(diffbuf, buflen + mb[i].size);
+ free(diffbuf);
+ diffbuf = NULL;
+ buflen = 0;
+ }
+ if (diffbuf) {
+ ((linediff_fn)priv)(diffbuf, buflen);
+ free(diffbuf);
+ diffbuf = NULL;
+ buflen = 0;
+ }
+ return 0;
+}
+
+int cgit_diff_files(const unsigned char *old_sha1,
+ const unsigned char *new_sha1,
+ linediff_fn fn)
+{
+ mmfile_t file1, file2;
+ xpparam_t diff_params;
+ xdemitconf_t emit_params;
+ xdemitcb_t emit_cb;
+
+ if (!load_mmfile(&file1, old_sha1) || !load_mmfile(&file2, new_sha1))
+ return 1;
+
+ diff_params.flags = XDF_NEED_MINIMAL;
+ emit_params.ctxlen = 3;
+ emit_params.flags = XDL_EMIT_FUNCNAMES;
+ emit_cb.outf = filediff_cb;
+ emit_cb.priv = fn;
+ xdl_diff(&file1, &file2, &diff_params, &emit_params, &emit_cb);
+ return 0;
+}
+
+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 && !is_null_sha1(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);
+}