1 files changed, 5 insertions, 4 deletions
diff --git a/erts/emulator/sys/win32/sys_float.c b/erts/emulator/sys/win32/sys_float.c
index 09dad89140..960edaa7a5 100644
--- a/erts/emulator/sys/win32/sys_float.c
+++ b/erts/emulator/sys/win32/sys_float.c
@@ -114,15 +114,16 @@ sys_chars_to_double(char *buf, double *fp)
 
 /* 
 ** Convert a double to ascii format 0.dddde[+|-]ddd
-** return number of characters converted
+** return number of characters converted or -1 if error.
 */
 
 int
-sys_double_to_chars(double fp, char *buffer, size_t buffer_size)
+sys_double_to_chars_ext(double fp, char *buffer, size_t buffer_size, size_t decimals)
 {
     char *s = buffer;
-    
-    (void) erts_snprintf(buffer, buffer_size, "%.20e", fp);
+
+    if (erts_snprintf(buffer, buffer_size, "%.*e", decimals, fp) >= buffer_size)
+        return -1;
     /* Search upto decimal point */
     if (*s == '+' || *s == '-') s++;
     while (isdigit(*s)) s++;