Commit 68978631 authored by Paul Eggert's avatar Paul Eggert

gtimezone: add support for RFC 8536 time zone transitions

Time zone transition times can range from -167:59:59 through
+167:59:59, according to Internet RFC 8536 section 3.3.1;
this is an extension to POSIX.  It is needed for proper
support of TZif version 3 files.
parent 325d17c4
......@@ -142,9 +142,7 @@ typedef struct
gint mday;
gint wday;
gint week;
gint hour;
gint min;
gint sec;
gint32 offset; /* hour*3600 + min*60 + sec; can be negative. */
} TimeZoneDate;
/* POSIX Timezone abbreviations are typically 3 or 4 characters, but
......@@ -289,10 +287,17 @@ g_time_zone_ref (GTimeZone *tz)
* - h[h] is 0 to 24
* - mm is 00 to 59
* - ss is 00 to 59
* If RFC8536, TIME_ is a transition time sans sign,
* so colons are required before mm and ss, and hh can be up to 167.
* See Internet RFC 8536 section 3.3.1:
* https://tools.ietf.org/html/rfc8536#section-3.3.1
* and POSIX Base Definitions 8.3 TZ rule time:
* https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03
*/
static gboolean
parse_time (const gchar *time_,
gint32 *offset)
gint32 *offset,
gboolean rfc8536)
{
if (*time_ < '0' || '9' < *time_)
return FALSE;
......@@ -310,7 +315,20 @@ parse_time (const gchar *time_,
*offset *= 10;
*offset += 60 * 60 * (*time_++ - '0');
if (*offset > 24 * 60 * 60)
if (rfc8536)
{
/* Internet RFC 8536 section 3.3.1 and POSIX 8.3 TZ together say
that a transition time must be of the form [+-]hh[:mm[:ss]] where
the hours part can range from -167 to 167. */
if ('0' <= *time_ && *time_ <= '9')
{
*offset *= 10;
*offset += 60 * 60 * (*time_++ - '0');
}
if (*offset > 167 * 60 * 60)
return FALSE;
}
else if (*offset > 24 * 60 * 60)
return FALSE;
if (*time_ == '\0')
......@@ -319,6 +337,8 @@ parse_time (const gchar *time_,
if (*time_ == ':')
time_++;
else if (rfc8536)
return FALSE;
if (*time_ < '0' || '5' < *time_)
return FALSE;
......@@ -335,6 +355,8 @@ parse_time (const gchar *time_,
if (*time_ == ':')
time_++;
else if (rfc8536)
return FALSE;
if (*time_ < '0' || '5' < *time_)
return FALSE;
......@@ -351,28 +373,32 @@ parse_time (const gchar *time_,
static gboolean
parse_constant_offset (const gchar *name,
gint32 *offset)
gint32 *offset,
gboolean rfc8536)
{
if (g_strcmp0 (name, "UTC") == 0)
/* Internet RFC 8536 section 3.3.1 and POSIX 8.3 TZ together say
that a transition time must be numeric. */
if (!rfc8536 && g_strcmp0 (name, "UTC") == 0)
{
*offset = 0;
return TRUE;
}
if (*name >= '0' && '9' >= *name)
return parse_time (name, offset);
return parse_time (name, offset, rfc8536);
switch (*name++)
{
case 'Z':
*offset = 0;
return !*name;
/* Internet RFC 8536 section 3.3.1 requires a numeric zone. */
return !rfc8536 && !*name;
case '+':
return parse_time (name, offset);
return parse_time (name, offset, rfc8536);
case '-':
if (parse_time (name, offset))
if (parse_time (name, offset, rfc8536))
{
*offset = -*offset;
return TRUE;
......@@ -391,7 +417,7 @@ zone_for_constant_offset (GTimeZone *gtz, const gchar *name)
gint32 offset;
TransitionInfo info;
if (name == NULL || !parse_constant_offset (name, &offset))
if (name == NULL || !parse_constant_offset (name, &offset, FALSE))
return;
info.gmt_offset = offset;
......@@ -590,9 +616,8 @@ init_zone_from_iana_info (GTimeZone *gtz,
static void
copy_windows_systemtime (SYSTEMTIME *s_time, TimeZoneDate *tzdate)
{
tzdate->sec = s_time->wSecond;
tzdate->min = s_time->wMinute;
tzdate->hour = s_time->wHour;
tzdate->offset
= s_time->wHour * 3600 + s_time->wMinute * 60 + s_time->wSecond;
tzdate->mon = s_time->wMonth;
tzdate->year = s_time->wYear;
tzdate->wday = s_time->wDayOfWeek ? s_time->wDayOfWeek : 7;
......@@ -979,7 +1004,7 @@ boundary_for_year (TimeZoneDate *boundary,
g_date_clear (&date, 1);
g_date_set_dmy (&date, buffer.mday, buffer.mon, buffer.year);
return ((g_date_get_julian (&date) - unix_epoch_start) * seconds_per_day +
buffer.hour * 3600 + buffer.min * 60 + buffer.sec - offset);
buffer.offset - offset);
}
static void
......@@ -1289,25 +1314,10 @@ parse_tz_boundary (const gchar *identifier,
/* Time */
if (*pos == '/')
{
gint32 offset;
if (!parse_time (++pos, &offset))
return FALSE;
boundary->hour = offset / 3600;
boundary->min = (offset / 60) % 60;
boundary->sec = offset % 3600;
return TRUE;
}
return parse_constant_offset (pos + 1, &boundary->offset, TRUE);
else
{
boundary->hour = 2;
boundary->min = 0;
boundary->sec = 0;
boundary->offset = 2 * 60 * 60;
return *pos == '\0';
}
}
......@@ -1341,7 +1351,7 @@ parse_offset (gchar **pos, gint32 *target)
++(*pos);
buffer = g_strndup (target_pos, *pos - target_pos);
ret = parse_constant_offset (buffer, target);
ret = parse_constant_offset (buffer, target, FALSE);
g_free (buffer);
return ret;
......
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