-LONGLONG_MIN is the undefined behavior in C.
longlong2decimal() used to do this:
int longlong2decimal(longlong from, decimal_t *to) {
if ((to->sign= from < 0))
return ull2dec(-from, to);
return ull2dec(from, to);
and later in ull2dec() (DIG_BASE is 1000000000):
static int ull2dec(ulonglong from, decimal_t *to) {
for (intg1=1; from >= DIG_BASE; intg1++, from/=DIG_BASE) {}
this breaks in gcc-5 at -O3. Here ull2dec is inlined into
longlong2decimal. And gcc-5 believes that 'from' in the
inlined ull2dec is always a positive integer (indeed, if it was
negative, then -from was used instead). So gcc-5 uses
*signed* comparison with DIG_BASE.
Fix: make a special case for LONGLONG_MIN, don't negate it
The collation customization code for the UCA (Unicode Collation Alrorithm)
based collations now allows to reset to and shift of characters with
implicit weights. Previously reset/shift worked only for the characters
with explicit DUCET weights. An attempt to use reset/shift with
character with implicit weights made the server crash.
In fact it was error in decimal library (incorrect processing of buffer overflow) invisible from other server parts because of buffer allocation and precision tests.
Note, the patch for MDEV-8661 unintentionally fixed MDEV-8694 as well,
as a side effect. Adding a real clear fix: implementing
Item_func_like::propagate_equal_fields() with comments.
This is a pre-requisite patch for:
- MDEV-8433 Make field<'broken-string' use indexes
- MDEV-8625 Bad result set with ignorable characters when using a prefix key
- MDEV-8626 Bad result set with contractions when using a prefix key
-LONGLONG_MIN is the undefined behavior in C.
longlong2decimal() used to do this:
int longlong2decimal(longlong from, decimal_t *to) {
if ((to->sign= from < 0))
return ull2dec(-from, to);
return ull2dec(from, to);
and later in ull2dec() (DIG_BASE is 1000000000):
static int ull2dec(ulonglong from, decimal_t *to) {
for (intg1=1; from >= DIG_BASE; intg1++, from/=DIG_BASE) {}
this breaks in gcc-5 at -O3. Here ull2dec is inlined into
longlong2decimal. And gcc-5 believes that 'from' in the
inlined ull2dec is always a positive integer (indeed, if it was
negative, then -from was used instead). So gcc-5 uses
*signed* comparison with DIG_BASE.
Fix: make a special case for LONGLONG_MIN, don't negate it
Adding a new virtual function MY_CHARSET_HANDLER::copy_abort().
Moving character set specific code into the correspoding implementations
(for simple, multi-byte and mbmaxlen>1 character sets).
