postgres.git / summary / log / commit / refs

commit    c79bdc9904afefeee495455be7dea737d714fbb4
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Tue Dec 01 16:42:25 2015 +0000

    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.


 src/interfaces/ecpg/pgtypeslib/numeric.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/interfaces/ecpg/pgtypeslib/numeric.c b/src/interfaces/ecpg/pgtypeslib/numeric.c
index 0504f3cac8a..d061616787e 100644
--- a/src/interfaces/ecpg/pgtypeslib/numeric.c
+++ b/src/interfaces/ecpg/pgtypeslib/numeric.c
@@ -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)


[parent: 6fe8ca0a2f8a]