Commit 043ea441 authored by peter@mysql.com's avatar peter@mysql.com
Browse files

Decimal field fix overflow

parent bac793e2

sql/field.cc

+16 −19
Original line number Diff line number Diff line
@@ -41,6 +41,11 @@ 
#include <floatingpoint.h>

#endif



// Maximum allowed exponent value for converting string to decimal

#define MAX_EXPONENT 1024







/*****************************************************************************

  Instansiate templates and static variables

*****************************************************************************/
@@ -367,7 +372,6 @@ void Field_decimal::store(const char *from,uint len) 
  /* The pointer where the field value starts (i.e., "where to write") */

  char *to=ptr;

  uint tmp_dec, tmp_uint;

  ulonglong tmp_ulonglong;

  /*

    The sign of the number : will be 0 (means positive but sign not

    specified), '+' or '-'
@@ -382,7 +386,6 @@ void Field_decimal::store(const char *from,uint len) 
 /* The sign of the exponent : will be 0 (means no exponent), '+' or '-' */

  char expo_sign_char=0;

  uint exponent=0;                                // value of the exponent

  ulonglong exponent_ulonglong=0;

  /*

    Pointers used when digits move from the left of the '.' to the

    right of the '.' (explained below)
@@ -485,14 +488,13 @@ void Field_decimal::store(const char *from,uint len) 
    */

    for (;from!=end && isdigit(*from); from++)

    {

      exponent_ulonglong=10*exponent_ulonglong+(ulonglong)(*from-'0');

      if (exponent_ulonglong>(ulonglong)UINT_MAX)

      exponent=10*exponent+(*from-'0');

      if (exponent>MAX_EXPONENT)

      {

        exponent_ulonglong=(ulonglong)UINT_MAX;

        exponent=MAX_EXPONENT;

        break;

      }

    }

    exponent=(uint)(exponent_ulonglong);

  }

  

  /*
@@ -534,21 +536,21 @@ void Field_decimal::store(const char *from,uint len) 
  */

  

  /* 

     Below tmp_ulongulong cannot overflow,

     Below tmp_uint cannot overflow with small enough MAX_EXPONENT setting,

     as int_digits_added_zeros<=exponent<4G and 

     (ulonglong)(int_digits_end-int_digits_from)<=max_allowed_packet<=2G and

     (ulonglong)(frac_digits_from-int_digits_tail_from)<=max_allowed_packet<=2G

  */



  if (!expo_sign_char)

    tmp_ulonglong=(ulonglong)tmp_dec+(ulonglong)(int_digits_end-int_digits_from);

    tmp_uint=tmp_dec+(uint)(int_digits_end-int_digits_from);

  else if (expo_sign_char == '-') 

  {

    tmp_uint=min(exponent,(uint)(int_digits_end-int_digits_from));

    frac_digits_added_zeros=exponent-tmp_uint;

    int_digits_end -= tmp_uint;

    frac_digits_head_end=int_digits_end+tmp_uint;

    tmp_ulonglong=(ulonglong)tmp_dec+(ulonglong)(int_digits_end-int_digits_from);     

    tmp_uint=tmp_dec+(uint)(int_digits_end-int_digits_from);     

  }

  else // (expo_sign_char=='+') 

  {
@@ -575,9 +577,9 @@ void Field_decimal::store(const char *from,uint len) 
	int_digits_added_zeros=0;

      }

    }

    tmp_ulonglong=(ulonglong)tmp_dec+(ulonglong)(int_digits_end-int_digits_from)

                 +(ulonglong)(frac_digits_from-int_digits_tail_from)+

                 (ulonglong)int_digits_added_zeros;

    tmp_uint=tmp_dec+(int_digits_end-int_digits_from)

                 +(uint)(frac_digits_from-int_digits_tail_from)+

                 int_digits_added_zeros;

  }

  

  /*
@@ -588,7 +590,7 @@ void Field_decimal::store(const char *from,uint len) 
    If the sign is defined and '-', we need one position for it

  */



  if ((ulonglong)field_length < tmp_ulonglong + (ulonglong) (sign_char == '-')) 

  if (field_length < tmp_uint + (sign_char == '-')) 

  //the rightmost sum above cannot overflow

  {

    // too big number, change to max or min number
@@ -596,11 +598,6 @@ void Field_decimal::store(const char *from,uint len) 
    return;

  }

 

  /*

    If the above test was ok, then tmp_ulonglong<4G and the following cast is valid

  */

  tmp_uint=(uint)tmp_ulonglong; 



  /*

    Tmp_left_pos is the position where the leftmost digit of

    the int_% parts will be written