Fixed BUILD script to use --with-berkeley-db instead of --with-bdb

Lots of small fixes to multi-precision-math path
Give Note for '123.4e'
Added helper functions type 'val_string_from_real()
Don't give warnings for end space for string2decimal()
Changed storage of values for SP so that we can detect length of argument without strlen()
Changed interface for str2dec() so that we must supple the pointer to the last character in the buffer



BUILD/SETUP.sh:
  with-bdb ->with-berkeley-db
include/decimal.h:
  Make string2decimal and string2decimal_fixed inline
mysql-test/r/func_group.result:
  More tests (to find bugs in precision math fixes)
mysql-test/r/func_set.result:
  Test to cover more Item_func_field::val_xxx() code
mysql-test/r/ps_6bdb.result:
  update results
mysql-test/r/type_decimal.result:
  New tests
  Give note for '123.4e'
mysql-test/r/type_newdecimal.result:
  Number of decimal changes (probably right, but hard to verify)
mysql-test/t/func_group.test:
  More tests (to find bugs in precision math fixes)
mysql-test/t/func_set.test:
  Test to cover more Item_func_field::val_xxx() code
mysql-test/t/type_decimal.test:
  New tests to cover more cases in decimal.c
sql/item.cc:
  Added helper functions type 'val_string_from_real()'
  Use new interfase to str2my_decimal()
  Moved nr_of_decimals() here (and made it static)
sql/item.h:
  Added helper functions type 'val_string_from_real()'
sql/item_func.cc:
  Style fixes
  Trivial optimizations
  Ensure null_value is set if my_decimal_add/sub/mul/div returns error
  Remove not needed Item_func_int_div::val_str()
  Join Item_func_signproc and Item_func_neg
  Fix that FIELD() works when first argument is NULL or one if it's arguments are NULL
  new str2my_decimal interface
sql/item_func.h:
  Make Item_func_int_div inherit from Item_int_func (allows us to remove some virtual functions)
  Join Item_func_signproc & Item_func_neg
sql/item_strfunc.cc:
  Move nr_of_decmails() to Item.cc (as it was only used here)
sql/item_sum.cc:
  Style fixes
  Change a lot of code to use new helper converter functions in item.cc
  Moved Item_sum::val_decimal() to Item_sum_int::val_decimal()
  Fixed calls to wrong functions (Item_sum_num::val_int())
  Ensure that all hybrid functions checks hybrid_type in val_xxx() (As there is no gurantee that they are called in the right context)
  Simplify key_length allocation in Item_sum_sum_distinct()
  Simplified create_tmp_field() and reset_field()
  Fixed potential error in Item_sum_hybrid::reset_field()
  Optimize Item_sum_avg::update_field()
  Item_std_field() functions musted be fully coded becasue Item_variance_field::val_xxx functions called helper functions
  Coded missing Item_sum_ufd_xxx::val_decimal() functions
sql/item_sum.h:
  Moved Item_sum::val_decimal() to Item_sum_int::val_decimal()
  Added missing Item_sum_ufd_xxx::val_decimal() functions
  Removed not used scale() function.
  Fixed that Item_std_field() works with decimal arguments
  Fixed that CREATE ... STD() will create a REAL field
sql/log_event.cc:
  Ensure that we use same format for all types
sql/my_decimal.cc:
  Don't give warnings for end space for string2decimal()
  Added dbug_print_decimal()
sql/my_decimal.h:
  Style fixes
  Prototypes for new functions
  New interface for str2my_decimal()
sql/mysql_priv.h:
  Made nr_of_decimals() static
sql/protocol.cc:
  Simplify code (by assume that decimal can't be bigger than DECIMAL_MAX_STR_LENGTH]
sql/protocol_cursor.cc:
  Changed storage of values for SP so that we can detect length of argument without strlen()
sql/sp_head.cc:
  Simplify code for decimal handling by letting item handling conversion to decimal
sql/sp_rcontext.cc:
  Use new method to get length of arguments
sql/sql_analyse.cc:
  if -> switch
  Increase 'empty' if decimal value=0
  Remove usage of strcat()
sql/sql_base.cc:
  Remove unnecessary checks
sql/sql_class.cc:
  Remove not needed 'else'
  Removed not used variables
sql/sql_select.cc:
  remove test for impossible condtion
strings/decimal.c:
  Made two trivial functions macros
  Changed interface for str2dec() so that we must supple the pointer to the last character in the buffer
  This safer than before as we don't require an end \0 anymore (old code gave wrong answers in MySQL for some internals strings that where not \0 terminated)
  Detect error numbers of type '12.55e'
  str2dec() will now set 'to' to zero in case of errors

include/decimal.h

@@ -17,7 +17,9 @@
 #ifndef _decimal_h
 #define _decimal_h
 
-typedef enum {TRUNCATE=0, HALF_EVEN, HALF_UP, CEILING, FLOOR} decimal_round_mode;
+typedef enum
+{TRUNCATE=0, HALF_EVEN, HALF_UP, CEILING, FLOOR}
+  decimal_round_mode;
 typedef int32 decimal_digit;
 
 typedef struct st_decimal {
@@ -26,11 +28,10 @@ typedef struct st_decimal {
   decimal_digit *buf;
 } decimal;
 
+int internal_str2dec(const char *from, decimal *to, char **end, my_bool fixed);
 int decimal2string(decimal *from, char *to, int *to_len,
                    int fixed_precision, int fixed_decimals,
                    char filler);
-int string2decimal(char *from, decimal *to, char **end);
-int string2decimal_fixed(char *from, decimal *to, char **end);
 int decimal2ulonglong(decimal *from, ulonglong *to);
 int ulonglong2decimal(ulonglong from, decimal *to);
 int decimal2longlong(decimal *from, longlong *to);
@@ -51,10 +52,14 @@ int decimal_cmp(decimal *from1, decimal *from2);
 int decimal_mul(decimal *from1, decimal *from2, decimal *to);
 int decimal_div(decimal *from1, decimal *from2, decimal *to, int scale_incr);
 int decimal_mod(decimal *from1, decimal *from2, decimal *to);
-int decimal_round(decimal *from, decimal *to, int new_scale, decimal_round_mode mode);
+int decimal_round(decimal *from, decimal *to, int new_scale,
+                  decimal_round_mode mode);
 int decimal_is_zero(decimal *from);
 void max_decimal(int precision, int frac, decimal *to);
 
+#define string2decimal(A,B,C) internal_str2dec((A), (B), (C), 0)
+#define string2decimal_fixed(A,B,C) internal_str2dec((A), (B), (C), 1)
+
 /* set a decimal to zero */
 
 #define decimal_make_zero(dec)        do {                \