More constructor error checking

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/unittest_tags/test_array.txt

@@ -337,6 +337,7 @@
 *graalpython.lib-python.3.test.test_array.LongTest.test_tofromlist
 *graalpython.lib-python.3.test.test_array.LongTest.test_type_error
 *graalpython.lib-python.3.test.test_array.LongTest.test_weakref
+*graalpython.lib-python.3.test.test_array.MiscTest.test_bad_constructor
 *graalpython.lib-python.3.test.test_array.MiscTest.test_empty
 *graalpython.lib-python.3.test.test_array.ShortTest.test_add
 *graalpython.lib-python.3.test.test_array.ShortTest.test_assignment

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

@@ -207,6 +207,9 @@ PArray arrayIteratorInitializer(VirtualFrame frame, Object cls, String typeCode,
             }
 
             private BufferFormat getFormatChecked(String typeCode) {
+                if (typeCode.length() != 1) {
+                    throw raise(TypeError, "array() argument 1 must be a unicode character, not str");
+                }
                 BufferFormat format = BufferFormat.forArray(typeCode);
                 if (format == null) {
                     throw raise(ValueError, "bad typecode (must be b, B, u, h, H, i, I, l, L, q, Q, f or d)");