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Do correct affinity transformations on floating point values which have

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a decimal point at the beginning or end of the mantissa.
Ticket [3998683a16a7076e08f5].

FossilOrigin-Name: ca154f97a590745539b2cbfd77eb319fd7392a40
This commit is contained in:
drh
2010-09-30 17:33:11 +00:00
parent 5f1d6b616e
commit 025586a259
6 changed files with 112 additions and 27 deletions
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45
src/util.c
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@@ -239,35 +239,47 @@ int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){
/*
** The string z[] is an text representation of a real number.
** Convert this string to a double.
** Convert this string to a double and write it into *pResult.
**
** The string z[] is length bytes in length (bytes, not characters) and
** uses the encoding enc. The string is not necessarily zero-terminated.
**
** Return TRUE if the result is a valid real number (or integer) and FALSE
** if the string is empty or contains extraneous text.
** if the string is empty or contains extraneous text. Valid numbers
** are in one of these formats:
**
** [+-]digits[E[+-]digits]
** [+-]digits.[digits][E[+-]digits]
** [+-].digits[E[+-]digits]
**
** Leading and trailing whitespace is ignored for the purpose of determining
** validity.
**
** If some prefix of the input string is a valid number, this routine
** returns FALSE but it still converts the prefix and writes the result
** into *pResult.
*/
int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){
#ifndef SQLITE_OMIT_FLOATING_POINT
int incr = (enc==SQLITE_UTF8?1:2);
const char *zEnd = z + length;
/* sign * significand * (10 ^ (esign * exponent)) */
int sign = 1; /* sign of significand */
i64 s = 0; /* significand */
int d = 0; /* adjust exponent for shifting decimal point */
int esign = 1; /* sign of exponent */
int e = 0; /* exponent */
int sign = 1; /* sign of significand */
i64 s = 0; /* significand */
int d = 0; /* adjust exponent for shifting decimal point */
int esign = 1; /* sign of exponent */
int e = 0; /* exponent */
int eValid = 1; /* True exponent is either not used or is well-formed */
double result;
int nDigits = 0;
*pResult = 0.0; /* Default return value, in case of an error */
if( enc==SQLITE_UTF16BE ) z++;
/* skip leading spaces */
while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;
if( z>=zEnd ){
*pResult = 0.0;
return 0;
}
if( z>=zEnd ) return 0;
/* get sign of significand */
if( *z=='-' ){
@@ -308,6 +320,7 @@ int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){
/* if exponent is present */
if( *z=='e' || *z=='E' ){
z+=incr;
eValid = 0;
if( z>=zEnd ) goto do_atof_calc;
/* get sign of exponent */
if( *z=='-' ){
@@ -320,9 +333,15 @@ int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){
while( z<zEnd && sqlite3Isdigit(*z) ){
e = e*10 + (*z - '0');
z+=incr;
eValid = 1;
}
}
/* skip trailing spaces */
if( nDigits && eValid ){
while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;
}
do_atof_calc:
/* adjust exponent by d, and update sign */
e = (e*esign) + d;
@@ -382,8 +401,8 @@ do_atof_calc:
/* store the result */
*pResult = result;
/* return true if number and no extra chracters after */
return z>=zEnd && sqlite3Isdigit(z[-incr]);
/* return true if number and no extra non-whitespace chracters after */
return z>=zEnd && nDigits>0 && eValid;
#else
return !sqlite3Atoi64(z, pResult, length, enc);
#endif /* SQLITE_OMIT_FLOATING_POINT */