diff options
Diffstat (limited to 'strings/strtod.c')
| -rw-r--r-- | strings/strtod.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/strings/strtod.c b/strings/strtod.c index 92d93612dd0..61f2c107abe 100644 --- a/strings/strtod.c +++ b/strings/strtod.c @@ -56,8 +56,8 @@ static double scaler1[] = { double my_strtod(const char *str, char **end_ptr, int *error) { double result= 0.0; - uint negative= 0, ndigits, dec_digits= 0, pre_zero, neg_exp= 0; - int exp= 0; + uint negative= 0, ndigits, dec_digits= 0, neg_exp= 0; + int exp= 0, digits_after_dec_point= 0; const char *old_str, *end= *end_ptr, *start_of_number; char next_char; my_bool overflow=0; @@ -100,18 +100,20 @@ double my_strtod(const char *str, char **end_ptr, int *error) } ndigits= (uint) (str-old_str); - pre_zero= 0; if (next_char == '.' && str < end-1) { - double p10= 10; + /* + Continue to add numbers after decimal point to the result, as if there + was no decimal point. We will later (in the exponent handling) shift + the number down with the required number of fractions. We do it this + way to be able to get maximum precision for numbers like 123.45E+02, + which are normal for some ODBC applications. + */ old_str= ++str; while (my_isdigit(&my_charset_latin1, (next_char= *str))) { - result+= (next_char - '0')/p10; - if (!result) - pre_zero++; - else - p10*= 10; + result= result*10.0 + (next_char - '0'); + digits_after_dec_point++; if (++str == end) { next_char= 0; @@ -136,13 +138,14 @@ double my_strtod(const char *str, char **end_ptr, int *error) { do { - if (exp < 9999) /* protec against exp overfl. */ - exp= exp*10 + *str - '0'; + if (exp < 9999) /* prot. against exp overfl. */ + exp= exp*10 + (*str - '0'); str++; } while (str < end && my_isdigit(&my_charset_latin1, *str)); } } - if ((exp= neg_exp ? exp + pre_zero : exp - pre_zero)) + if ((exp= (neg_exp ? exp + digits_after_dec_point : + exp - digits_after_dec_point))) { double scaler; if (exp < 0) |