[cp-patches] Patch: Calendar fixes

[Bryce McKinlay]

This patch fixes some small Calendar problems, including the DST rollover issue 
reported by Martin Egholm Nielsen. Calendar.set did not invalidate the 
DST_OFFSET field even though changing other fields could roll the time over a 
DST boundary. Thus, computeTime() would apply the DST offset to the resulting 
Date value even if the date was no longer in a DST period. I've checked in a 
mauve test for this issue. Also, this patch contains a minor spec fix for 
GregorianCalendar.add().

Bryce



2004-10-08  Bryce McKinlay  <address@hidden>

        * java/util/Calendar.java (set): Invalidate DST_OFFSET
        field as a DST boundary may have been crossed.
        * java/util/GregorianCalendar.java (add): Throw 
        IllegalArgumentException on attempt to add to DST_OFFSET or 
        ZONE_OFFSET fields. Update javadoc.

Index: Calendar.java
===================================================================
RCS file: /cvs/gcc/gcc/libjava/java/util/Calendar.java,v
retrieving revision 1.23
diff -u -r1.23 Calendar.java
--- Calendar.java       29 Aug 2004 17:28:09 -0000      1.23
+++ Calendar.java       8 Oct 2004 23:22:17 -0000
@@ -651,6 +651,10 @@
        isSet[HOUR_OF_DAY] = false;
        break;
       }
+
+    // May have crossed over a DST boundary.
+    if (field != DST_OFFSET && field != ZONE_OFFSET)
+      isSet[DST_OFFSET] = false;
   }
 
   /**
@@ -671,6 +675,8 @@
     isSet[WEEK_OF_MONTH] = false;
     isSet[DAY_OF_WEEK] = false;
     isSet[DAY_OF_WEEK_IN_MONTH] = false;
+
+    isSet[DST_OFFSET] = false;  // May have crossed a DST boundary.
   }
 
   /**
Index: GregorianCalendar.java
===================================================================
RCS file: /cvs/gcc/gcc/libjava/java/util/GregorianCalendar.java,v
retrieving revision 1.22
diff -u -r1.22 GregorianCalendar.java
--- GregorianCalendar.java      10 Jul 2004 02:23:40 -0000      1.22
+++ GregorianCalendar.java      8 Oct 2004 23:22:17 -0000
@@ -540,7 +540,7 @@
     fields[DAY_OF_WEEK] = weekday;
 
     // get a first approximation of the year.  This may be one 
-    // year to big.
+    // year too big.
     int year = 1970 + (gregorian
                       ? ((day - 100) * 400) / (365 * 400 + 100 - 4 + 1)
                       : ((day - 100) * 4) / (365 * 4 + 1));
@@ -709,6 +709,10 @@
    * it does what you expect: Jan, 25 + 10 Days is Feb, 4.
    * @param field the time field. One of the time field constants.
    * @param amount the amount of time.
+   * @exception IllegalArgumentException if <code>field</code> is 
+   *   <code>ZONE_OFFSET</code>, <code>DST_OFFSET</code>, or invalid; or
+   *   if <code>amount</code> contains an out-of-range value and the calendar
+   *   is not in lenient mode.
    */
   public void add(int field, int amount)
   {
@@ -785,18 +789,9 @@
        areFieldsSet = false;
        break;
       case ZONE_OFFSET:
-       complete();
-       fields[ZONE_OFFSET] += amount;
-       time -= amount;
-       break;
       case DST_OFFSET:
-       complete();
-       fields[DST_OFFSET] += amount;
-       isTimeSet = false;
-       break;
       default:
-       throw new IllegalArgumentException
-         ("Unknown Calendar field: " + field);
+       throw new IllegalArgumentException("Invalid or unknown field");
       }
   }