Fix setting date properties from an empty date object.

If $date->month is set, before $date->mday is set it was incorrectly
being adjusted down. This would happen, e.g., when creating a new
date object, with no parameters then manually setting the month
property before setting the mday property.

framework/Date/lib/Horde/Date.php

@@ -1114,7 +1114,9 @@ protected function _correct($mask = self::MASK_ALLPARTS, $down = false)
             $this->_correctMonth();
             /* When correcting the month, always correct the day too. Months
              * have different numbers of days. */
-            $mask |= self::MASK_DAY;
+            if (!empty($this->_mday)) {
+                $mask |= self::MASK_DAY;
+            }
         }
 
         if ($mask & self::MASK_DAY) {

framework/Date/test/Horde/Date/DateTest.php

@@ -142,6 +142,15 @@ public function testDateCorrection()
         $this->assertEquals(28, $d->day);
     }
 
+    public function testSettingDatePropertiesFromEmptyDateObject()
+    {
+        $d = new Horde_Date();
+        $d->year = 2013;
+        $d->month = 12;
+        $d->mday = 20;
+        $this->assertEquals(12, $d->month);
+    }
+
     public function testTimestamp()
     {
         $oldTimezone = date_default_timezone_get();