Fixed integer overflow in interval typecaster

Close #512.

3 files changed, 9 insertions, 4 deletions

diff --git a/NEWS b/NEWS
index 52868e9..8fc14cd 100644
--- a/NEWS
+++ b/NEWS
@@ -47,6 +47,7 @@ Bug fixes:
 
 - Fixed error caused by missing decoding `~psycopg2.extras.LoggingConnection`
   (:ticket:`#483`).
+- Fixed integer overflow in :sql:`interval` seconds (:ticket:`#512`).
 
 Other changes:
 
diff --git a/psycopg/typecast_datetime.c b/psycopg/typecast_datetime.c
index ad74101..6b94175 100644
--- a/psycopg/typecast_datetime.c
+++ b/psycopg/typecast_datetime.c
@@ -220,10 +220,10 @@ typecast_PYTIME_cast(const char *str, Py_ssize_t len, PyObject *curs)
 static PyObject *
 typecast_PYINTERVAL_cast(const char *str, Py_ssize_t len, PyObject *curs)
 {
-    long years = 0, months = 0, days = 0;
+    long years = 0, months = 0, days = 0, sec;
     double hours = 0.0, minutes = 0.0, seconds = 0.0, hundredths = 0.0;
     double v = 0.0, sign = 1.0, denominator = 1.0;
-    int part = 0, sec;
+    int part = 0;
     double micro;
 
     if (str == NULL) { Py_RETURN_NONE; }
@@ -318,8 +318,8 @@ typecast_PYINTERVAL_cast(const char *str, Py_ssize_t len, PyObject *curs)
     days += years*365 + months*30;
 
     micro = (seconds - floor(seconds)) * 1000000.0;
-    sec = (int)floor(seconds);
-    return PyObject_CallFunction((PyObject*)PyDateTimeAPI->DeltaType, "iii",
+    sec = (long)floor(seconds);
+    return PyObject_CallFunction((PyObject*)PyDateTimeAPI->DeltaType, "lli",
                                  days, sec, (int)round(micro));
 }
 
diff --git a/tests/test_dates.py b/tests/test_dates.py
index 3463d00..8bb03c7 100755
--- a/tests/test_dates.py
+++ b/tests/test_dates.py
@@ -333,6 +333,10 @@ class DatetimeTests(ConnectingTestCase, CommonDatetimeTestsMixin):
         t = self.execute("select '24:00+05:30'::timetz;")
         self.assertEqual(t, time(0, 0, tzinfo=FixedOffsetTimezone(330)))
 
+    def test_large_interval(self):
+        t = self.execute("select '999999:00:00'::interval")
+        self.assertEqual(t.days * 24 + t.seconds / 60.0 / 60, 999999)
+
 
 # Only run the datetime tests if psycopg was compiled with support.
 if not hasattr(psycopg2.extensions, 'PYDATETIME'):