Wrap some lines and add comments

h2/src/main/org/h2/expression/Function.java

@@ -1811,7 +1811,9 @@ public class Function extends Expression implements FunctionCall {
                 (count > Integer.MAX_VALUE || count < Integer.MIN_VALUE)) {
             throw DbException.getInvalidValueException("DATEADD count", count);
         }
-        boolean withDate = !(v instanceof ValueTime), withTime = !(v instanceof ValueDate), forceTimestamp = false;
+        boolean withDate = !(v instanceof ValueTime);
+        boolean withTime = !(v instanceof ValueDate);
+        boolean forceTimestamp = false;
         long[] a = DateTimeUtils.dateAndTimeFromValue(v);
         long dateValue = a[0];
         long timeNanos = a[1];

h2/src/main/org/h2/util/DateTimeUtils.java

@@ -922,7 +922,13 @@ public class DateTimeUtils {
         if (month != 2) {
             return NORMAL_DAYS_PER_MONTH[month];
         }
-        return (year & 3) == 0 && (year < 1582 || year % 100 != 0 || year % 400 == 0) ? 29 : 28;
+        // All leap years divisible by 4
+        return (year & 3) == 0
+                // All such years before 1582 are Julian and leap
+                && (year < 1582
+                        // Otherwise check Gregorian conditions
+                        || year % 100 != 0 || year % 400 == 0)
+                ? 29 : 28;
     }
 
     /**
@@ -1068,7 +1074,9 @@ public class DateTimeUtils {
     }
 
     /**
-     * Get the date value from a given denormalized date.
+     * Get the date value from a given denormalized date with possible out of range
+     * values of month and/or day. Used after addition or subtraction month or years
+     * to (from) it to get a valid date.
      *
      * @param year
      *            the year