commit b6855150397a86da84c30d1144075d4609b339be
author Benjamin Peterson <benjamin@python.org> Thu Sep 10 21:02:39 2015 -0700
committer Benjamin Peterson <benjamin@python.org> Thu Sep 10 21:02:39 2015 -0700
tree 4a951462295e339535e03bb26967ee5583fcd9ea
parent 508a81e0944a8332936273810f14c9bdcd9d434f

compute stack effect of BUILD_MAP correctly (closes #25060)

Python/compile.c

diff --git a/Python/compile.c b/Python/compile.c
index cfeab0f..97bb12e 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -985,7 +985,7 @@
         case BUILD_MAP_UNPACK_WITH_CALL:
             return 1 - (oparg & 0xFF);
         case BUILD_MAP:
-            return 1;
+            return 1 - 2*oparg;
         case LOAD_ATTR:
             return 0;
         case COMPARE_OP: