diff --git a/mercurial/cext/revlog.c b/mercurial/cext/revlog.c
--- a/mercurial/cext/revlog.c
+++ b/mercurial/cext/revlog.c
@@ -163,9 +163,6 @@
 		return nullentry;
 	}
 
-	if (pos < 0)
-		pos += length;
-
 	if (pos < 0 || pos >= length) {
 		PyErr_SetString(PyExc_IndexError, "revlog index out of range");
 		return NULL;
diff --git a/mercurial/pure/parsers.py b/mercurial/pure/parsers.py
--- a/mercurial/pure/parsers.py
+++ b/mercurial/pure/parsers.py
@@ -48,8 +48,6 @@
     def _fix_index(self, i):
         if not isinstance(i, int):
             raise TypeError("expecting int indexes")
-        if i < 0:
-            i = len(self) + i
         if i < 0 or i >= len(self):
             raise IndexError
         return i