Bug#25739702 ENABLE UBSAN ON 32BIT PLATFORMS

Increase DEFAULT_THREAD_STACK for 32bit UBSAN builds.
Also: fix my_convert() which did unaligned read/write.
Also: fix signed integer overflow in TIME_to_gmt_sec() and
      Time_zone_offset::TIME_to_gmt_sec()

Author: Tor Didriksen

include/my_thread.h

@@ -51,6 +51,8 @@
 */
 #if defined(__sparc) && (defined(__SUNPRO_CC) || defined(__SUNPRO_C))
 #define STACK_MULTIPLIER 2UL
+#elif defined HAVE_UBSAN && SIZEOF_CHARP == 4
+#define STACK_MULTIPLIER 3UL
 #else
 #define STACK_MULTIPLIER 1UL
 #endif

sql/log.cc

@@ -1476,7 +1476,7 @@ bool Query_logger::slow_log_write(THD *thd, const char *query,
        *current_handler ;)
   {
     error|= (*current_handler++)->log_slow(thd, current_utime,
-                                           (thd->start_time.tv_sec * 1000000) +
+                                           (thd->start_time.tv_sec * 1000000ULL) +
                                            thd->start_time.tv_usec,
                                            user_host_buff, user_host_len,
                                            query_utime, lock_utime, is_command,

sql/tztime.cc

@@ -953,7 +953,7 @@ static my_time_t
 TIME_to_gmt_sec(const MYSQL_TIME *t, const TIME_ZONE_INFO *sp,
                 bool *in_dst_time_gap)
 {
-  my_time_t local_t;
+  longlong local_t;
   uint saved_seconds;
   uint i;
   int shift= 0;
@@ -1036,16 +1036,16 @@ TIME_to_gmt_sec(const MYSQL_TIME *t, const TIME_ZONE_INFO *sp,
       beginning of the gap.
     */
     *in_dst_time_gap= 1;
-    local_t= sp->revts[i] - sp->revtis[i].rt_offset + saved_seconds;
+    local_t= sp->revts[i] + saved_seconds - sp->revtis[i].rt_offset;
   }
   else
-    local_t= local_t - sp->revtis[i].rt_offset + saved_seconds;
+    local_t= local_t + saved_seconds - sp->revtis[i].rt_offset;
 
   /* check for TIMESTAMP_MAX_VALUE was already done above */
   if (local_t < TIMESTAMP_MIN_VALUE)
     local_t= 0;
 
-  DBUG_RETURN(local_t);
+  DBUG_RETURN(static_cast<my_time_t>(local_t));
 }
 
 
@@ -1418,7 +1418,7 @@ Time_zone_offset::TIME_to_gmt_sec(
   const MYSQL_TIME *t,
   bool *in_dst_time_gap MY_ATTRIBUTE((unused))) const
 {
-  my_time_t local_t;
+  longlong local_t;
   int shift= 0;
 
   /*
@@ -1447,7 +1447,7 @@ Time_zone_offset::TIME_to_gmt_sec(
   }
 
   if (local_t >= TIMESTAMP_MIN_VALUE && local_t <= TIMESTAMP_MAX_VALUE)
-    return local_t;
+    return static_cast<my_time_t>(local_t);
 
   /* range error*/
   return 0;

strings/ctype.cc

@@ -1041,7 +1041,7 @@ my_convert(char *to, size_t to_length, const CHARSET_INFO *to_cs,
 
   length= length2= MY_MIN(to_length, from_length);
 
-#if defined(__i386__)
+#if defined(__i386__) || defined(_WIN32) || defined(__x86_64__)
   /*
     Special loop for i386, it allows to refer to a
     non-aligned memory block as UINT32, which makes
@@ -1051,9 +1051,9 @@ my_convert(char *to, size_t to_length, const CHARSET_INFO *to_cs,
   */
   for ( ; length >= 4; length-= 4, from+= 4, to+= 4)
   {
-    if ((*(uint32*)from) & 0x80808080)
+    if (uint4korr(from) & 0x80808080)
       break;
-    *((uint32*) to)= *((const uint32*) from);
+    int4store(to, uint4korr(from));
   }
 #endif /* __i386__ */