new file mode 100644
--- /dev/null
+++ b/mercurial/mpatch.h
@@ -0,0 +1,20 @@
+#ifndef _HG_MPATCH_H_
+#define _HG_MPATCH_H_
+
+struct mpatch_frag {
+	int start, end, len;
+	const char *data;
+};
+
+struct mpatch_flist {
+	struct mpatch_frag *base, *head, *tail;
+};
+
+int mpatch_decode(const char *bin, ssize_t len, struct mpatch_flist** res);
+ssize_t mpatch_calcsize(ssize_t len, struct mpatch_flist *l);
+void mpatch_lfree(struct mpatch_flist *a);
+int mpatch_apply(char *buf, const char *orig, ssize_t len,
+	struct mpatch_flist *l);
+struct mpatch_flist *mpatch_fold(void *bins, ssize_t start, ssize_t end);
+
+#endif