[libxslt] Fix unsigned integer overflow in date.c

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 0921b596cc897ebc1fd57988b475aa7b430812f0
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Thu May 16 21:19:55 2019 +0200

    Fix unsigned integer overflow in date.c

 libexslt/date.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/libexslt/date.c b/libexslt/date.c
index d075adc5..60deffff 100644
--- a/libexslt/date.c
+++ b/libexslt/date.c
@@ -141,9 +141,9 @@ struct _exsltDateDurVal {
 #define IS_LEAP(y)                                             \
        (((y & 3) == 0) && ((y % 25 != 0) || ((y & 15) == 0)))
 
-static const unsigned long daysInMonth[12] =
+static const long daysInMonth[12] =
        { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
-static const unsigned long daysInMonthLeap[12] =
+static const long daysInMonthLeap[12] =
        { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
 
 #define MAX_DAYINMONTH(yr,mon)                                  \
@@ -177,9 +177,9 @@ static const unsigned long daysInMonthLeap[12] =
 #define DAYS_PER_EPOCH          (400 * 365 + 100 - 4 + 1)
 #define YEARS_PER_EPOCH         400
 
-static const unsigned long dayInYearByMonth[12] =
+static const long dayInYearByMonth[12] =
        { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
-static const unsigned long dayInLeapYearByMonth[12] =
+static const long dayInLeapYearByMonth[12] =
        { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 };
 
 #define DAY_IN_YEAR(day, month, year)                          \