Add checks for edge cases in datetime.timestamp and datetime.astimezone methods

Author: donBarbos

Lib/_pydatetime.py

@@ -1990,7 +1990,10 @@ def _mktime(self):
         t = (self - epoch) // timedelta(0, 1)
         def local(u):
             y, m, d, hh, mm, ss = _time.localtime(u)[:6]
-            return (datetime(y, m, d, hh, mm, ss) - epoch) // timedelta(0, 1)
+            try:
+                return (datetime(y, m, d, hh, mm, ss) - epoch) // timedelta(0, 1)
+            except (ValueError, OverflowError):
+                return u
 
         # Our goal is to solve t = local(u) for u.
         a = local(t) - t

Modules/_datetimemodule.c

@@ -5415,6 +5415,7 @@ local(long long u)
 {
     struct tm local_time;
     time_t t;
+    long long old_u = u;
     u -= epoch;
     t = u;
     if (t != u) {
@@ -5424,7 +5425,13 @@ local(long long u)
     }
     if (_PyTime_localtime(t, &local_time) != 0)
         return -1;
-    return utc_to_seconds(local_time.tm_year + 1900,
+
+    // Check edge cases
+    int year = local_time.tm_year + 1900;
+    if (year < MINYEAR || year > MAXYEAR) {
+        return old_u;
+    }
+    return utc_to_seconds(year,
                           local_time.tm_mon + 1,
                           local_time.tm_mday,
                           local_time.tm_hour,