Please describe the problem:
g_array_insert_vals(array,index,data,len) inserts len elements into a GArray at a given index. No check is made whether the index is actually outside of the current array length (array->len), which can lead to a segfault in g_memmove. Also, some functions in garray.c seem to check if the array is null and others do not.

I propose to add the following lines at the beginning of g_array_insert_vals
inspired by those found in g_array_remove_index:

g_return_val_if_fail (array != NULL, NULL);
g_return_val_if_fail (index <= array->len, NULL);

Steps to reproduce:
#include <glib.h>

int main(void)
{
    int value = 12345;
    GArray *array = NULL;

    array = g_array_new(FALSE, TRUE, sizeof(int));

    g_array_insert_val(array, 1, value);

    g_array_free(array, TRUE);
    return 0;
}

Actual results:
Results in a segmentation fault when a bad length value is sent to g_memmove in g_array_insert_vals. 

Expected results:
That the function g_array_insert_vals reports the error and returns a NULL pointer.

Does this happen every time?


Other information: