[Python-checkins] get_gmtoff() now returns time_t (GH-10838)

Fri Nov 30 18:39:41 EST 2018

https://github.com/python/cpython/commit/503ce5c482cb267b0770bc46c315d5cf822bdca9
commit: 503ce5c482cb267b0770bc46c315d5cf822bdca9
branch: master
author: Victor Stinner <vstinner at redhat.com>
committer: GitHub <noreply at github.com>
date: 2018年12月01日T00:39:36+01:00
summary:
get_gmtoff() now returns time_t (GH-10838)
get_gmtoff() now returns time_t instead of int to fix the following
Visual Studio warning:
 Modules\timemodule.c(1183): warning C4244: 'return':
 conversion from 'time_t' to 'int', possible loss of data
files:
M Modules/timemodule.c

diff --git a/Modules/timemodule.c b/Modules/timemodule.c
index 55b82d74cb19..188f1e6ef571 100644
--- a/Modules/timemodule.c
+++ b/Modules/timemodule.c
@@ -1019,7 +1019,7 @@ of the timezone or altzone attributes on the time module.");
 #endif /* HAVE_MKTIME */
 
 #ifdef HAVE_WORKING_TZSET
-static void PyInit_timezone(PyObject *module);
+static int PyInit_timezone(PyObject *module);
 
 static PyObject *
 time_tzset(PyObject *self, PyObject *unused)
@@ -1034,7 +1034,9 @@ time_tzset(PyObject *self, PyObject *unused)
 tzset();
 
 /* Reset timezone, altzone, daylight and tzname */
- PyInit_timezone(m);
+ if (PyInit_timezone(m) < 0) {
+ return NULL;
+ }
 Py_DECREF(m);
 if (PyErr_Occurred())
 return NULL;
@@ -1535,7 +1537,7 @@ get_zone(char *zone, int n, struct tm *p)
 #endif
 }
 
-static int
+static time_t
 get_gmtoff(time_t t, struct tm *p)
 {
 #ifdef HAVE_STRUCT_TM_TM_ZONE
@@ -1546,8 +1548,11 @@ get_gmtoff(time_t t, struct tm *p)
 }
 #endif // !HAVE_DECL_TZNAME
 
-static void
-PyInit_timezone(PyObject *m) {
+static int
+PyInit_timezone(PyObject *m)
+{
+ assert(!PyErr_Occurred());
+
 /* This code moved from PyInit_time wholesale to allow calling it from
 time_tzset. In the future, some parts of it can be moved back
 (for platforms that don't HAVE_WORKING_TZSET, when we know what they
@@ -1591,19 +1596,31 @@ PyInit_timezone(PyObject *m) {
 static const time_t YEAR = (365 * 24 + 6) * 3600;
 time_t t;
 struct tm p;
- long janzone, julyzone;
+ time_t janzone_t, julyzone_t;
 char janname[10], julyname[10];
 t = (time((time_t *)0) / YEAR) * YEAR;
 _PyTime_localtime(t, &p);
 get_zone(janname, 9, &p);
- janzone = -get_gmtoff(t, &p);
+ janzone_t = -get_gmtoff(t, &p);
 janname[9] = '0円';
 t += YEAR/2;
 _PyTime_localtime(t, &p);
 get_zone(julyname, 9, &p);
- julyzone = -get_gmtoff(t, &p);
+ julyzone_t = -get_gmtoff(t, &p);
 julyname[9] = '0円';
 
+ /* Sanity check, don't check for the validity of timezones.
+ In practice, it should be more in range -12 hours .. +14 hours. */
+#define MAX_TIMEZONE (48 * 3600)
+ if (janzone_t < -MAX_TIMEZONE || janzone_t > MAX_TIMEZONE
+ || julyzone_t < -MAX_TIMEZONE || julyzone_t > MAX_TIMEZONE)
+ {
+ PyErr_SetString(PyExc_RuntimeError, "invalid GMT offset");
+ return -1;
+ }
+ int janzone = (int)janzone_t;
+ int julyzone = (int)julyzone_t;
+
 PyObject *tzname_obj;
 if (janzone < julyzone) {
 /* DST is reversed in the southern hemisphere */
@@ -1617,10 +1634,16 @@ PyInit_timezone(PyObject *m) {
 PyModule_AddIntConstant(m, "daylight", janzone != julyzone);
 tzname_obj = Py_BuildValue("(zz)", janname, julyname);
 }
- if (tzname_obj == NULL)
- return;
+ if (tzname_obj == NULL) {
+ return -1;
+ }
 PyModule_AddObject(m, "tzname", tzname_obj);
 #endif // !HAVE_DECL_TZNAME
+
+ if (PyErr_Occurred()) {
+ return -1;
+ }
+ return 0;
 }
 
 
@@ -1721,7 +1744,9 @@ PyInit_time(void)
 return NULL;
 
 /* Set, or reset, module variables like time.timezone */
- PyInit_timezone(m);
+ if (PyInit_timezone(m) < 0) {
+ return NULL;
+ }
 
 #if defined(HAVE_CLOCK_GETTIME) || defined(HAVE_CLOCK_SETTIME) || defined(HAVE_CLOCK_GETRES)
 
