Fix: shrink array if varargs are less than expected

Author: fangerer

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/PythonCextBuiltins.java

@@ -3338,17 +3338,22 @@ static Object callFunction(VirtualFrame frame, Object callable, Object vaList,
                      */
                     long arraySize = argsArrayLib.getArraySize(vaList);
                     Object[] args = new Object[PInt.intValueExact(arraySize) - 1];
+                    int filled = 0;
                     for (int i = 0; i < args.length; i++) {
                         try {
                             Object object = argsArrayLib.readArrayElement(vaList, i);
                             if (argLib.isNull(object)) {
                                 break;
                             }
                             args[i] = asPythonObjectNode.execute(object);
+                            filled++;
                         } catch (InvalidArrayIndexException e) {
                             throw CompilerDirectives.shouldNotReachHere();
                         }
                     }
+                    if (filled < args.length) {
+                        args = PythonUtils.arrayCopyOf(args, filled);
+                    }
                     return callableLib.callObject(callable, frame, args);
                 } catch (UnsupportedMessageException | OverflowException e) {
                     // I think we can just assume that there won't be more than