Commit d8ba8b8c authored by unknown's avatar unknown
Browse files

Bug#26536 func_time failure on vm-win2003-64-b, occurs every time 

 - Avoid overflow in sec_since_epoch by shifting the time
   back 2 days for times close to the maximum range of my_time_t
 - Improve comment about why we need my_time_t
 - Patch will also fix timezone2.test


include/my_time.h:
  Improve comment for my_time_t, especially that we require
  it to be at least a 32bit unsigned type
sql/tztime.cc:
  - Add assert in sec_since_epoch to guard it against broken down time
  values that would cause overflow in my_time_t on systems with 32 bit
  my_time_t
  - Avoid overflow in sec_since_epoch by "shifting" the broken down
  time back 2 days for times that are near the max value.c
parent 44994c9d

include/my_time.h

+7 −1
Original line number Diff line number Diff line
@@ -30,7 +30,13 @@ extern uchar days_in_month[]; 


/*

  Portable time_t replacement.

  Should be signed and hold seconds for 1902-2038 range.

  Should be signed and hold seconds for 1902 -- 2038-01-19 range

  i.e at least a 32bit variable



  Using the system built in time_t is not an option as

  we rely on the above requirements in the time functions



  For example QNX has an unsigned time_t type

*/

typedef long my_time_t;

sql/tztime.cc

+20 −3
Original line number Diff line number Diff line
@@ -780,6 +780,8 @@ gmt_sec_to_TIME(TIME *tmp, my_time_t sec_in_utc, const TIME_ZONE_INFO *sp) 
static my_time_t

sec_since_epoch(int year, int mon, int mday, int hour, int min ,int sec)

{

  /* Guard against my_time_t overflow(on system with 32 bit my_time_t) */

  DBUG_ASSERT(!(year == TIMESTAMP_MAX_YEAR && mon == 1 && mday > 17));

#ifndef WE_WANT_TO_HANDLE_UNORMALIZED_DATES

  /*

    It turns out that only whenever month is normalized or unnormalized
@@ -948,12 +950,12 @@ TIME_to_gmt_sec(const TIME *t, const TIME_ZONE_INFO *sp, 
  */

  if (shift)

  {

    if (local_t > (my_time_t) (TIMESTAMP_MAX_VALUE - shift*86400L +

    if (local_t > (my_time_t) (TIMESTAMP_MAX_VALUE - shift * SECS_PER_DAY +

                               sp->revtis[i].rt_offset - saved_seconds))

    {

      DBUG_RETURN(0);                           /* my_time_t overflow */

    }

    local_t+= shift*86400L;

    local_t+= shift * SECS_PER_DAY;

  }



  if (sp->revtis[i].rt_type)
@@ -1341,6 +1343,7 @@ my_time_t 
Time_zone_offset::TIME_to_gmt_sec(const TIME *t, my_bool *in_dst_time_gap) const

{

  my_time_t local_t;

  int shift= 0;



  /*

    Check timestamp range.we have to do this as calling function relies on
@@ -1349,10 +1352,24 @@ Time_zone_offset::TIME_to_gmt_sec(const TIME *t, my_bool *in_dst_time_gap) const 
  if (!validate_timestamp_range(t))

    return 0;



  local_t= sec_since_epoch(t->year, t->month, t->day,

  /*

    Do a temporary shift of the boundary dates to avoid

    overflow of my_time_t if the time value is near it's

    maximum range

  */

  if ((t->year == TIMESTAMP_MAX_YEAR) && (t->month == 1) && t->day > 4)

    shift= 2;



  local_t= sec_since_epoch(t->year, t->month, (t->day - shift),

                           t->hour, t->minute, t->second) -

           offset;



  if (shift)

  {

    /* Add back the shifted time */

    local_t+= shift * SECS_PER_DAY;

  }



  if (local_t >= TIMESTAMP_MIN_VALUE && local_t <= TIMESTAMP_MAX_VALUE)

    return local_t;