Report prescan errors on their source lines

tests/struct_types.c

@@ -218,6 +218,22 @@ static void test_declaration_errors_are_basic_errors(void)
     }
 }
 
+/** @brief A field declaration error reports the field's source line. */
+static void test_type_prescan_error_line(void)
+{
+    TEST_REQUIRE_OK(harness_start(NULL));
+    TEST_REQUIRE_OK(akbasic_runtime_load(&HARNESS_RUNTIME,
+					 "10 TYPE RECT\n"
+					 "20 W# EXTRA\n"
+					 "30 END TYPE\n"
+					 "40 PRINT 1\n"));
+    TEST_REQUIRE_OK(akbasic_runtime_start(&HARNESS_RUNTIME, AKBASIC_MODE_RUN));
+    TEST_REQUIRE(strstr(HARNESS_OUTPUT, "? 20 : PARSE ERROR") != NULL,
+		 "TYPE prescan should report its source line, got \"%s\"",
+		 HARNESS_OUTPUT);
+    harness_stop();
+}
+
 /**
  * @brief An over-long type or field name is refused, not silently trimmed.
  *
@@ -270,6 +286,7 @@ int main(void)
     test_missing_field_lists_the_others();
     test_self_by_value_refused();
     test_declaration_errors_are_basic_errors();
+    test_type_prescan_error_line();
     test_long_names_are_refused();
 
     return akbasic_test_failures;