diff options
| -rw-r--r-- | misc/bstr.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/misc/bstr.c b/misc/bstr.c index 13441eede9..1a2676c537 100644 --- a/misc/bstr.c +++ b/misc/bstr.c @@ -401,15 +401,21 @@ void bstr_xappend_vasprintf(void *talloc_ctx, bstr *s, const char *fmt, int size; va_list copy; va_copy(copy, ap); + size_t avail = talloc_get_size(s->start) - s->len; + char *dest = s->start ? s->start + s->len : NULL; char c; - size = vsnprintf(&c, 1, fmt, copy); + if (avail < 1) + dest = &c; + size = vsnprintf(dest, MPMAX(avail, 1), fmt, copy); va_end(copy); if (size < 0) abort(); - resize_append(talloc_ctx, s, size + 1); - vsnprintf(s->start + s->len, size + 1, fmt, ap); + if (avail < 1 || size + 1 > avail) { + resize_append(talloc_ctx, s, size + 1); + vsnprintf(s->start + s->len, size + 1, fmt, ap); + } s->len += size; } |