Use "g" not "f" format in ecpg's PGTYPESnumeric_from_double().

The previous coding could overrun the provided buffer size for a very large
input, or lose precision for a very small input.  Adopt the methodology
that's been in use in the equivalent backend code for a long time.

Per private report from Bas van Schaik.  Back-patch to all supported
branches.
This commit is contained in:
Tom Lane 2015-12-01 11:42:25 -05:00
parent 2287b87454
commit db4a5cfc76

View File

@ -2,6 +2,7 @@
#include "postgres_fe.h"
#include <ctype.h>
#include <float.h>
#include <limits.h>
#include "extern.h"
@ -1497,11 +1498,11 @@ PGTYPESnumeric_copy(numeric *src, numeric *dst)
int
PGTYPESnumeric_from_double(double d, numeric *dst)
{
char buffer[100];
char buffer[DBL_DIG + 100];
numeric *tmp;
int i;
if (sprintf(buffer, "%f", d) == 0)
if (sprintf(buffer, "%.*g", DBL_DIG, d) <= 0)
return -1;
if ((tmp = PGTYPESnumeric_from_asc(buffer, NULL)) == NULL)