pythongh-117534: Add checking for input parameter in iso_to_ymd (updated)

Author: Vlad4896

Lib/test/datetimetester.py

@@ -1928,6 +1928,7 @@ def test_fromisoformat_fails(self):
             '2019-W53-1',       # No week 53 in 2019
             '2020-W54-1',       # No week 54
             '2009\ud80002\ud80028',     # Separators are surrogate codepoints
+            '0000W25',          # Invalid year
         ]
 
         for bad_str in bad_strs:

Modules/_datetimemodule.c

@@ -416,8 +416,9 @@ iso_week1_monday(int year)
 static int
 iso_to_ymd(const int iso_year, const int iso_week, const int iso_day,
            int *year, int *month, int *day) {
-    if (iso_year <= 0) {
-        return -2;
+    // Year is bounded to 0 < year < 10000 because 9999-12-31 is (9999, 52, 5)
+    if (iso_year < MINYEAR || iso_year > MAXYEAR) {
+        return -4;
     }
     if (iso_week <= 0 || iso_week >= 53) {
         int out_of_range = 1;
@@ -765,7 +766,7 @@ parse_isoformat_date(const char *dtstr, const size_t len, int *year, int *month,
      *      -2:  Inconsistent date separator usage
      *      -3:  Failed to parse ISO week.
      *      -4:  Failed to parse ISO day.
-     *      -5, -6: Failure in iso_to_ymd
+     *      -5, -6, -7: Failure in iso_to_ymd
      */
     const char *p = dtstr;
     p = parse_digits(p, year, 4);
@@ -3145,15 +3146,13 @@ date_fromisocalendar(PyObject *cls, PyObject *args, PyObject *kw)
         return NULL;
     }
 
-    // Year is bounded to 0 < year < 10000 because 9999-12-31 is (9999, 52, 5)
-    if (year < MINYEAR || year > MAXYEAR) {
-        PyErr_Format(PyExc_ValueError, "Year is out of range: %d", year);
-        return NULL;
-    }
-
     int month;
     int rv = iso_to_ymd(year, week, day, &year, &month, &day);
 
+    if (rv == -4) {
+        PyErr_Format(PyExc_ValueError, "Year is out of range: %d", year);
+        return NULL;
+    }
 
     if (rv == -2) {
         PyErr_Format(PyExc_ValueError, "Invalid week: %d", week);