Fix uninitialized memory read reported by Valgrind when running doctest.

nnorwitz · nnorwitz · commit 7e49c6eee88c · 2006-07-12T05:27:46.000Z
This could happen if size == 0.
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
@@ -556,6 +556,7 @@ PyCode_CheckLineNumber(PyCodeObject* co, int lasti, PyAddrPair *bounds)
            the line increments here, treating them as byte
            increments gets confusing, to say the least. */
 
+        bounds->ap_lower = 0;
         while (size > 0) {
                 if (addr + *p > lasti)
                         break;
