cal: fix broken computation for Sep 1752

Signed-off-by: Peter Breitenlohner <peb@mppmu.mpg.de>
Signed-off-by: Pádraig Brady <P@draigBrady.com>

diff --git a/misc-utils/cal.c b/misc-utils/cal.c
index 3e38f8ed7a4424fdd140df221697176b8cebb258..bda3a9633a40cc39660ba54273fade85b3d411d6 100644 (file)
--- a/misc-utils/cal.c
+++ b/misc-utils/cal.c
@@ -162,7 +162,7 @@ char                *Hrow;          /* pointer to highlighted row in month */
 #define        FIRST_MISSING_DAY       639799          /* 3 Sep 1752 */
 #define        NUMBER_MISSING_DAYS     11              /* 11 day correction */
 
-#define        MAXDAYS                 43              /* max slots in a month array */
+#define        MAXDAYS                 42              /* slots in a month array */
 #define        SPACE                   -1              /* used in day array */
 
 static int days_in_month[2][13] = {
@@ -170,30 +170,34 @@ static int days_in_month[2][13] = {
        {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
 };
 
-int sep1752[MAXDAYS] = {
+#define SEP1752_OFS            4               /* sep1752[4] is a Sunday */
+
+/* 1 Sep 1752 is represented by sep1752[6] and j_sep1752[6] */
+int sep1752[MAXDAYS+6] = {
+                               SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  1,      2,      14,     15,     16,
        17,     18,     19,     20,     21,     22,     23,
        24,     25,     26,     27,     28,     29,     30,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
-       SPACE
-}, j_sep1752[MAXDAYS] = {
+       SPACE,  SPACE
+}, j_sep1752[MAXDAYS+6] = {
+                               SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  245,    246,    258,    259,    260,
        261,    262,    263,    264,    265,    266,    267,
        268,    269,    270,    271,    272,    273,    274,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
-       SPACE
+       SPACE,  SPACE
 }, empty[MAXDAYS] = {
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
        SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
-       SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,
-       SPACE
+       SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE,  SPACE
 };
 
 #define        DAY_LEN         3               /* 3 spaces per day */
@@ -629,10 +633,11 @@ day_array(int day, int month, int year, int *days) {
        int *d_sep1752;
 
        if (month == 9 && year == 1752) {
+               int sep1752_ofs = (weekstart + SEP1752_OFS) % 7;
                d_sep1752 = julian ? j_sep1752 : sep1752;
-               memcpy(days, d_sep1752 + weekstart, MAXDAYS * sizeof(int));
+               memcpy(days, d_sep1752 + sep1752_ofs, MAXDAYS * sizeof(int));
                for (dm=0; dm<MAXDAYS; dm++)
-                       if (j_sep1752[dm] == day)
+                       if (j_sep1752[dm + sep1752_ofs] == day)
                                days[dm] |= TODAY_FLAG;
                return;
        }