From 8f2b022b06701a69524560651ae038a04533f69e Mon Sep 17 00:00:00 2001
From: Ryan Baumann <ryan.baumann@gmail.com>
Date: Thu, 8 Oct 2015 14:45:59 -0400
Subject: [PATCH] Correctly handle BCE leap years in call to GregorianCalendar
 isLeapYear(), according to XSD 1.0 Second Edition spec

---
 .../com/thaiopensource/datatype/xsd/DateTimeDatatype.java   | 3 +++
 mod/xsd-datatype/test/xsdtest.xml                           | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/mod/xsd-datatype/src/main/com/thaiopensource/datatype/xsd/DateTimeDatatype.java b/mod/xsd-datatype/src/main/com/thaiopensource/datatype/xsd/DateTimeDatatype.java
index 42daa4e82..b09f6f618 100644
--- a/mod/xsd-datatype/src/main/com/thaiopensource/datatype/xsd/DateTimeDatatype.java
+++ b/mod/xsd-datatype/src/main/com/thaiopensource/datatype/xsd/DateTimeDatatype.java
@@ -252,6 +252,9 @@ private static Date createDate(GregorianCalendar cal, int tzOffset, boolean nega
     month -= 1;
     cal.set(year, month, day, hours, minutes, seconds);
     cal.set(Calendar.MILLISECOND, milliseconds);
+    if (negative) {
+      year = -(year - 1);
+    }
     checkDate(cal.isLeapYear(year), month, day); // for GCJ
     return cal.getTime();
   }
diff --git a/mod/xsd-datatype/test/xsdtest.xml b/mod/xsd-datatype/test/xsdtest.xml
index 5bbba48da..1a22e085b 100644
--- a/mod/xsd-datatype/test/xsdtest.xml
+++ b/mod/xsd-datatype/test/xsdtest.xml
@@ -214,6 +214,12 @@
 <datatype name="date">
 <valid>1886-12-01</valid>
 <valid>1886-12-01Z</valid>
+<valid>0004-02-29</valid>
+<valid>-0001-02-29</valid>
+<valid>-0257-02-29</valid>
+<invalid>0003-02-29</invalid>
+<invalid>-0257-02-30</invalid>
+<invalid>-0258-02-29</invalid>
 <lessThan>
   <value>1066-12-31</value>
   <value>1900-01-01</value>