Old variable definition not removed and was hiding function parameter…

…. If

variable definition attained a non null value, code could also crash. In
worst case, if neither handler or filter specified, result would have been
value of PythonInterpPerDirective setting. The latter shouldn't in practice
occur but cater for it anyway. (MODPYTHON-103)

src/mod_python.c

@@ -1260,14 +1260,15 @@ static const char *select_interp_name(request_rec *req, conn_rec *con,
              * global interpreter.
              */
 
-            py_handler *fh;
-
             if (fh) {
                 s = fh->directory;
             }
             else if (hle) {
                 s = hle->directory;
             }
+            else {
+                return NULL;
+            }
 
             if (s && (s[0] == '\0'))
                 return NULL;