# HG changeset patch
# User Martin von Zweigbergk <martinvonz@google.com>
# Date 2017-06-24 05:15:22
# Node ID a10f5f6771f67ac560e589c6a841fbebd573ca3d
# Parent  ce96efec81121eab1c8ee3ff223a924530322400

dagop: raise ProgrammingError if stopdepth < 0

revset.py should never send such a value.

diff --git a/mercurial/dagop.py b/mercurial/dagop.py
--- a/mercurial/dagop.py
+++ b/mercurial/dagop.py
@@ -32,8 +32,10 @@ def _genrevancestors(repo, revs, followf
         startdepth = 0
     if stopdepth is None:
         stopdepth = _maxlogdepth
-    if stopdepth <= 0:
+    if stopdepth == 0:
         return
+    if stopdepth < 0:
+        raise error.ProgrammingError('negative stopdepth')
 
     cl = repo.changelog