py/vstr: vstr_null_terminated_str(): Extend string by at most one byte.
vstr_null_terminated_str is almost certainly a vstr finalization operation,
so it should add the requested NUL byte, and not try to pre-allocate more.
The previous implementation could actually allocate double of the buffer
size.
diff --git a/py/vstr.c b/py/vstr.c
index 3367ae5..f558e3f 100644
--- a/py/vstr.c
+++ b/py/vstr.c
@@ -181,9 +181,15 @@
// Doesn't increase len, just makes sure there is a null byte at the end
char *vstr_null_terminated_str(vstr_t *vstr) {
- if (vstr->had_error || !vstr_ensure_extra(vstr, 1)) {
+ if (vstr->had_error) {
return NULL;
}
+ // If there's no more room, add single byte
+ if (vstr->alloc == vstr->len) {
+ if (vstr_extend(vstr, 1) == NULL) {
+ return NULL;
+ }
+ }
vstr->buf[vstr->len] = '\0';
return vstr->buf;
}