resize on unowned arrays should not be allowed

Vala code:

void func(int[] arr) {
    arr.resize(2000);
    stdout.printf("Length after resize: %d\n", arr.length);
}

void main() {
    int[] arr = new int[1];
    func(arr);
    stdout.printf("Length in main: %d\n", arr.length);
}

Generated C code:

void
func (gint* arr,
      gint arr_length1)
{
	gint _tmp0_;
	FILE* _tmp1_;
	_tmp0_ = 2000;
	arr = g_renew (gint, arr, 2000);
	(_tmp0_ > arr_length1) ? memset (arr + arr_length1, 0, sizeof (gint) * (_tmp0_ - arr_length1)) : NULL;
	arr_length1 = _tmp0_;
	_tmp1_ = stdout;
	fprintf (_tmp1_, "Length after resize: %d\n", arr_length1);
}

void
_vala_main (void)
{
	gint* arr = NULL;
	gint* _tmp0_;
	gint arr_length1;
	gint _arr_size_;
	FILE* _tmp1_;
	_tmp0_ = g_new0 (gint, 1);
	arr = _tmp0_;
	arr_length1 = 1;
	_arr_size_ = arr_length1;
	func (arr, (gint) arr_length1);
	_tmp1_ = stdout;
	fprintf (_tmp1_, "Length in main: %d\n", arr_length1);
	arr = (g_free (arr), NULL);
}

Output:

Length after resize: 2000
Length in main: 1

Valgrind also reports a memory leak.

Since resize ultimately calls realloc, the allocation is moved and since an unowned reference doesn't include the pointer to the owned reference variable, it's impossible to support reallocations for this case.