Add an option to calculate easter dates based on the Gregorian calendar

during the years 1582-1752. Earlier this was only possible from
1753 onwards. Use the optional parameter CAL_EASTER_ROMAN with
easter_days() to enable this. This is a fix for bug #12766.
# As you can see, my Sundays are *so* busy...

3 files changed, 29 insertions, 19 deletions

diff --git a/ext/calendar/calendar.c b/ext/calendar/calendar.c
index 000918d7f1..d5a346c056 100644
--- a/ext/calendar/calendar.c
+++ b/ext/calendar/calendar.c
@@ -127,7 +127,11 @@ PHP_MINIT_FUNCTION(calendar)
 	REGISTER_LONG_CONSTANT("CAL_MONTH_JULIAN_LONG",		CAL_MONTH_JULIAN_LONG, CONST_CS|CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("CAL_MONTH_JEWISH",			CAL_MONTH_JEWISH, CONST_CS|CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("CAL_MONTH_FRENCH",			CAL_MONTH_FRENCH, CONST_CS|CONST_PERSISTENT);
-
+	/* constants for easter calculation */
+	REGISTER_LONG_CONSTANT("CAL_EASTER_DEFAULT",			CAL_EASTER_DEFAULT, CONST_CS | CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("CAL_EASTER_ROMAN",				CAL_EASTER_ROMAN, CONST_CS | CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("CAL_EASTER_ALWAYS_GREGORIAN",	CAL_EASTER_ALWAYS_GREGORIAN, CONST_CS | CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("CAL_EASTER_ALWAYS_JULIAN",		CAL_EASTER_ALWAYS_JULIAN, CONST_CS | CONST_PERSISTENT);
 	return SUCCESS;
 }
 
diff --git a/ext/calendar/easter.c b/ext/calendar/easter.c
index 0a2121e751..baf4919cc0 100644
--- a/ext/calendar/easter.c
+++ b/ext/calendar/easter.c
@@ -29,36 +29,27 @@ static void _cal_easter(INTERNAL_FUNCTION_PARAMETERS, int gm)
 
 	/* based on code by Simon Kershaw, <webmaster@ely.anglican.org> */
 
-	pval *year_arg;
 	struct tm *ta, te;
 	time_t the_time;
 	long year, golden, solar, lunar, pfm, dom, tmp, easter;
+	long method = CAL_EASTER_DEFAULT;
 
-	switch(ZEND_NUM_ARGS()) {
-	case 0:
-		the_time = time(NULL);
-		ta = localtime(&the_time);
-		year = ta->tm_year + 1900;
-		break;
-	case 1:
-		if (getParameters(ht, 1, &year_arg) == FAILURE) {
-			WRONG_PARAM_COUNT;
-		}
-		convert_to_long(year_arg);
-		year = Z_LVAL_P(year_arg);
-		break;
-	default:
-		WRONG_PARAM_COUNT;
+	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC,
+		"l|l", &year, &method) == FAILURE) {
+			return;
 	}
  
 	if (gm && (year<1970 || year>2037)) {				/* out of range for timestamps */
-		php3_error(E_WARNING, "easter_date() is only valid for years between 1970 and 2037 inclusive");
+		php_error(E_WARNING, "easter_date() is only valid for years between 1970 and 2037 inclusive");
 		RETURN_FALSE;
 	}
 
 	golden = (year % 19) + 1;					/* the Golden number */
 
-	if ( year <= 1752 ) {						/* JULIAN CALENDAR */
+	if ((year <= 1582 && method != CAL_EASTER_ALWAYS_GREGORIAN) ||
+	    (year >= 1583 && year <= 1752 && method != CAL_EASTER_ROMAN && method != CAL_EASTER_ALWAYS_GREGORIAN) ||
+	     method == CAL_EASTER_ALWAYS_JULIAN) {		/* JULIAN CALENDAR */
+	     
 		dom = (year + (year/4) + 5) % 7;			/* the "Dominical number" - finding a Sunday */
 		if (dom < 0) {
 			dom += 7;
diff --git a/ext/calendar/php_calendar.h b/ext/calendar/php_calendar.h
index 73bc96aede..79c9edf73c 100644
--- a/ext/calendar/php_calendar.h
+++ b/ext/calendar/php_calendar.h
@@ -32,4 +32,19 @@ PHP_FUNCTION(cal_info);
 
 #define phpext_calendar_ptr calendar_module_ptr
 
+/*
+ * Specifying the easter calculation method
+ * 
+ * DEFAULT is Anglican, ie. use Julian calendar before 1753
+ * and Gregorian after that. With ROMAN, the cutoff year is 1582.
+ * ALWAYS_GREGORIAN and ALWAYS_JULIAN force the calendar
+ * regardless of date.
+ *
+ */
+ 
+#define CAL_EASTER_DEFAULT			0
+#define CAL_EASTER_ROMAN			1
+#define CAL_EASTER_ALWAYS_GREGORIAN	2
+#define CAL_EASTER_ALWAYS_JULIAN	3
+
 #endif