--- a/mercurial/bdiff.c	Fri Nov 04 21:44:25 2016 -0700
+++ b/mercurial/bdiff.c	Sun Nov 06 18:51:57 2016 -0800
@@ -17,6 +17,10 @@
 #include "bitmanipulation.h"
 #include "bdiff.h"
 
+/* Hash implementation from diffutils */
+#define ROL(v, n) ((v) << (n) | (v) >> (sizeof(v) * CHAR_BIT - (n)))
+#define HASH(h, c) ((c) + ROL(h ,7))
+
 struct pos {
 	int pos, len;
 };
@@ -44,8 +48,7 @@
 	/* build the line array and calculate hashes */
 	hash = 0;
 	for (p = a; p < a + len; p++) {
-		/* Leonid Yuriev's hash */
-		hash = (hash * 1664525) + (unsigned char)*p + 1013904223;
+		hash = HASH(hash, *p);
 
 		if (*p == '\n' || p == plast) {
 			l->hash = hash;