+
+/* this is like vsnprintf but the 'n' limit does not include
+ the terminating null. So if you have a 1024 byte buffer then
+ pass 1023 for n */
+int vslprintf(char *str, int n, const char *format, va_list ap)
+{
+#ifdef HAVE_VSNPRINTF
+ int ret = vsnprintf(str, n, format, ap);
+ if (ret > n || ret < 0) {
+ str[n] = 0;
+ return -1;
+ }
+ str[ret] = 0;
+ return ret;
+#else
+ static char *buf;
+ static int len=MAXPATHLEN*8;
+ int ret;
+
+ /* this code is NOT a proper vsnprintf() implementation. It
+ relies on the fact that all calls to slprintf() in rsync
+ pass strings which have already been checked to be less
+ than MAXPATHLEN in length and never more than 2 strings are
+ concatenated. This means the above buffer is absolutely
+ ample and can never be overflowed.
+
+ In the future we would like to replace this with a proper
+ vsnprintf() implementation but right now we need a solution
+ that is secure and portable. This is it. */
+
+ if (!buf) {
+ buf = malloc(len);
+ if (!buf) {
+ /* can't call debug or we would recurse */
+ exit(1);
+ }
+ }
+
+ ret = vsprintf(buf, format, ap);
+
+ if (ret < 0) {
+ str[0] = 0;
+ return -1;
+ }
+
+ if (ret < n) {
+ n = ret;
+ } else if (ret > n) {
+ ret = -1;
+ }
+
+ buf[n] = 0;
+
+ memcpy(str, buf, n+1);
+
+ return ret;
+#endif
+}
+
+
+/* like snprintf but always null terminates */
+int slprintf(char *str, int n, char *format, ...)
+{
+ va_list ap;
+ int ret;
+
+ va_start(ap, format);
+ ret = vslprintf(str,n,format,ap);
+ va_end(ap);
+ return ret;
+}