common/buf.c: use 0 directly in vsnprintf()

This works around a wrong truncation warning in older GCC versions:
```
../src/common/buf.c:110:10: error: null destination pointer [-Werror=format-truncation=]
  110 |  int n = vsnprintf(NULL, size, fmt, ap)
```
This commit is contained in:
Consolatis 2024-08-23 20:09:47 +02:00
parent b667107d1a
commit 23a9df0f30

View file

@ -103,18 +103,17 @@ buf_add_fmt(struct buf *s, const char *fmt, ...)
if (string_null_or_empty(fmt)) {
return;
}
size_t size = 0;
va_list ap;
va_start(ap, fmt);
int n = vsnprintf(NULL, size, fmt, ap);
int n = vsnprintf(NULL, 0, fmt, ap);
va_end(ap);
if (n < 0) {
return;
}
size = (size_t)n + 1;
size_t size = (size_t)n + 1;
buf_expand(s, s->len + size);
va_start(ap, fmt);