Bugfix: #18532

Fixed week number calculation in accordance with ISO 8601

diff --git a/ext/standard/datetime.c b/ext/standard/datetime.c
index cb78fc400c2036a26e5702cc13067f3f9f4c1fc6..758666a13ac6c9fd294cf64aa0a1a556f0f8a7d7 100644 (file)
--- a/ext/standard/datetime.c
+++ b/ext/standard/datetime.c
@@ -66,6 +66,7 @@ static int phpday_tab[2][12] =
 };
 
 #define isleap(year) (((year%4) == 0 && (year%100)!=0) || (year%400)==0)
+#define YEAR_BASE 1900
 
 /* {{{ proto int time(void)
    Return current UNIX timestamp */
@@ -395,7 +396,7 @@ php_date(INTERNAL_FUNCTION_PARAMETERS, int gm)
                                strcat(Z_STRVAL_P(return_value), day_full_names[ta->tm_wday]);
                                break;
                        case 'Y':               /* year, numeric, 4 digits */
-                               sprintf(tmp_buff, "%d", ta->tm_year + 1900);  /* SAFE */
+                               sprintf(tmp_buff, "%d", ta->tm_year + YEAR_BASE);  /* SAFE */
                                strcat(Z_STRVAL_P(return_value), tmp_buff);
                                break;
                        case 'M':               /* month, textual, 3 letters */
@@ -481,7 +482,7 @@ php_date(INTERNAL_FUNCTION_PARAMETERS, int gm)
                                }
                                break;
                        case 't':               /* days in current month */
-                               sprintf(tmp_buff, "%2d", phpday_tab[isleap((ta->tm_year+1900))][ta->tm_mon] );
+                               sprintf(tmp_buff, "%2d", phpday_tab[isleap((ta->tm_year+YEAR_BASE))][ta->tm_mon] );
                                strcat(Z_STRVAL_P(return_value), tmp_buff);
                                break;
                        case 'w':               /* day of the week, numeric EXTENSION */
@@ -505,7 +506,7 @@ php_date(INTERNAL_FUNCTION_PARAMETERS, int gm)
                                strcat(Z_STRVAL_P(return_value), tmp_buff);
                                break;
                        case 'L':               /* boolean for leapyear */
-                               sprintf(tmp_buff, "%d", (isleap((ta->tm_year+1900)) ? 1 : 0 ) );
+                               sprintf(tmp_buff, "%d", (isleap((ta->tm_year+YEAR_BASE)) ? 1 : 0 ) );
                                strcat(Z_STRVAL_P(return_value), tmp_buff);
                                break;
                        case 'T':               /* timezone name */
@@ -535,7 +536,7 @@ php_date(INTERNAL_FUNCTION_PARAMETERS, int gm)
                                        day_short_names[ta->tm_wday],
                                        ta->tm_mday,
                                        mon_short_names[ta->tm_mon],
-                                       ta->tm_year + 1900,
+                                       ta->tm_year + YEAR_BASE,
                                        ta->tm_hour,
                                        ta->tm_min,
                                        ta->tm_sec,
@@ -548,7 +549,7 @@ php_date(INTERNAL_FUNCTION_PARAMETERS, int gm)
                                        day_short_names[ta->tm_wday],
                                        ta->tm_mday,
                                        mon_short_names[ta->tm_mon],
-                                       ta->tm_year + 1900,
+                                       ta->tm_year + YEAR_BASE,
                                        ta->tm_hour,
                                        ta->tm_min,
                                        ta->tm_sec,
@@ -560,13 +561,24 @@ php_date(INTERNAL_FUNCTION_PARAMETERS, int gm)
                                strcat(Z_STRVAL_P(return_value), tmp_buff);
                                break;
                        case 'W':               /* ISO-8601 week number of year, weeks starting on Monday */
-                               wd = ta->tm_wday==0 ? 7 : ta->tm_wday;
-                               yd = ta->tm_yday + 1;
-                               fd = (7 + (wd - yd) % 7 ) % 7;
-                               wk = ( (yd + fd - 1) / 7 ) + 1;
-                               if (fd>3) {
-                                       wk--;
+                               wd = ta->tm_wday==0 ? 6 : ta->tm_wday-1;/* weekday */
+                               yd = ta->tm_yday + 1;                                   /* days since January 1st */
+
+                               fd = (7 + wd - yd % 7+ 1) % 7;                  /* weekday (1st January) */     
+
+                               /* week is a last year week (52 or 53) */
+                               if ((yd <= 7 - fd) && fd > 3){                  
+                                       wk = (fd == 4 || (fd == 5 && isleap((ta->tm_year + YEAR_BASE - 1)))) ? 53 : 52;
+                               }
+                               /* week is a next year week (1) */
+                               else if (isleap((ta->tm_year+YEAR_BASE)) + 365 - yd < 3 - wd){
+                                       wk = 1;
                                }
+                               /* normal week */
+                               else {
+                                       wk = (yd + 6 - wd + fd) / 7 - (fd > 3);
+                               }
+
                                sprintf(tmp_buff, "%d", wk);  /* SAFE */
                                strcat(Z_STRVAL_P(return_value), tmp_buff);
                                break;