V4 Date.ParseString(): fix UTC-ness of date-only formats

ECMA-262 stipulates that date-only formats should be treated as UTC,
while date-times are handled as standard time, if no time zone is
explicitly given.  Tidied up the parser a bit in the process and
documented what the spec says.  Fixed some broken test-cases.

Handling of date-times without zone as local time is a correction
since edition 5.1 of ECMA-262 (which said to handle it as UTC):
http://www.ecma-international.org/ecma-262/7.0/index.html#sec-corrections-and-clarifications-in-ecmascript-2015-with-possible-compatibility-impact
We were previously handling both dates and date-times as local time,
violating the old spec for both and the revised spec for dates.

Task-number: QTBUG-56787
Change-Id: I557789d855b910ca6a859fca396af1a0205c9417
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 11 insertions, 8 deletions

diff --git a/tests/auto/qml/qqmlecmascript/data/assignDate.qml b/tests/auto/qml/qqmlecmascript/data/assignDate.qml
index 14fe20787b..73677e99f1 100644
--- a/tests/auto/qml/qqmlecmascript/data/assignDate.qml
+++ b/tests/auto/qml/qqmlecmascript/data/assignDate.qml
@@ -7,28 +7,31 @@ MyTypeObject {
         var dateTimeVar = new Date("2009-05-12T00:00:01")
         var dateTimeVar2 = new Date("2009-05-12T23:59:59")
 
+        // Date, with no zone specified, is implicitly UTC
         dateProperty = dateVar
+        // Date-time, with no zone, is implicitly local-time
         dateTimeProperty = dateTimeVar
         dateTimeProperty2 = dateTimeVar2
 
-        // Commented properties do not currently test true:
-        boolProperty = //(dateProperty.getTime() == dateVar.getTime()) &&
+        boolProperty = (dateProperty.getTime() == dateVar.getTime()) &&
                        (dateProperty.getFullYear() == 2009) &&
                        (dateProperty.getMonth() == 5-1) &&
-                       //(dateProperty.getDate() == 12) &&
-                       (dateProperty.getHours() == 0) &&
+                       (dateProperty.getDate() == 12) &&
+                       (dateProperty.getUTCHours() == 0) &&
+                       (dateProperty.getUTCMinutes() == 0) &&
+                       (dateProperty.getUTCSeconds() == 0) &&
                        (dateTimeProperty.getTime() == dateTimeVar.getTime()) &&
                        (dateTimeProperty.getFullYear() == 2009) &&
                        (dateTimeProperty.getMonth() == 5-1) &&
-                       //(dateTimeProperty.getDate() == 12) &&
-                       //(dateTimeProperty.getHours() == 0) &&
+                       (dateTimeProperty.getDate() == 12) &&
+                       (dateTimeProperty.getHours() == 0) &&
                        (dateTimeProperty.getMinutes() == 0) &&
                        (dateTimeProperty.getSeconds() == 1) &&
                        (dateTimeProperty2.getTime() == dateTimeVar2.getTime()) &&
                        (dateTimeProperty2.getFullYear() == 2009) &&
                        (dateTimeProperty2.getMonth() == 5-1) &&
-                       //(dateTimeProperty2.getDate() == 12) &&
-                       //(dateTimeProperty2.getHours() == 23) &&
+                       (dateTimeProperty2.getDate() == 12) &&
+                       (dateTimeProperty2.getHours() == 23) &&
                        (dateTimeProperty2.getMinutes() == 59) &&
                        (dateTimeProperty2.getSeconds() == 59)
     }