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Bug#39828 : Autoinc wraps around when offset and increment > 1

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Auto increment value wraps when performing a bulk insert with
auto_increment_increment and auto_increment_offset greater than
one.
The fix:
If overflow happened then return MAX_ULONGLONG value as an
indication of overflow and check this before storing the
value into the field in update_auto_increment().
This commit is contained in:
Sergey Glukhov
2010-12-13 14:48:12 +03:00
parent 4096f35a39
commit 0e77c3295a
7 changed files with 88 additions and 118 deletions
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30
sql/handler.cc
View File

@ -2166,7 +2166,8 @@ int handler::read_first_row(uchar * buf, uint primary_key)
computes the lowest number
- strictly greater than "nr"
- of the form: auto_increment_offset + N * auto_increment_increment
If overflow happened then return MAX_ULONGLONG value as an
indication of overflow.
In most cases increment= offset= 1, in which case we get:
@verbatim 1,2,3,4,5,... @endverbatim
If increment=10 and offset=5 and previous number is 1, we get:
@ -2175,13 +2176,23 @@ int handler::read_first_row(uchar * buf, uint primary_key)
inline ulonglong
compute_next_insert_id(ulonglong nr,struct system_variables *variables)
{
const ulonglong save_nr= nr;
if (variables->auto_increment_increment == 1)
return (nr+1); // optimization of the formula below
nr= (((nr+ variables->auto_increment_increment -
variables->auto_increment_offset)) /
(ulonglong) variables->auto_increment_increment);
return (nr* (ulonglong) variables->auto_increment_increment +
variables->auto_increment_offset);
nr= nr + 1; // optimization of the formula below
else
{
nr= (((nr+ variables->auto_increment_increment -
variables->auto_increment_offset)) /
(ulonglong) variables->auto_increment_increment);
nr= (nr* (ulonglong) variables->auto_increment_increment +
variables->auto_increment_offset);
}
if (unlikely(nr <= save_nr))
return ULONGLONG_MAX;
return nr;
}
@ -2392,7 +2403,7 @@ int handler::update_auto_increment()
variables->auto_increment_increment,
nb_desired_values, &nr,
&nb_reserved_values);
if (nr == ~(ulonglong) 0)
if (nr == ULONGLONG_MAX)
DBUG_RETURN(HA_ERR_AUTOINC_READ_FAILED); // Mark failure
/*
@ -2423,6 +2434,9 @@ int handler::update_auto_increment()
}
}
if (unlikely(nr == ULONGLONG_MAX))
DBUG_RETURN(HA_ERR_AUTOINC_ERANGE);
DBUG_PRINT("info",("auto_increment: %lu", (ulong) nr));
if (unlikely(table->next_number_field->store((longlong) nr, TRUE)))