gbytearray: Do not accept too large byte arrays

GByteArray uses guint for storing the length of the byte array, but it
also has a constructor (g_byte_array_new_take) that takes length as a
gsize. gsize may be larger than guint (64 bits for gsize vs 32 bits
for guint). It is possible to call the function with a value greater
than G_MAXUINT, which will result in silent length truncation. This
may happen as a result of unreffing GBytes into GByteArray, so rather
be loud about it.

(Test case tweaked by Philip Withnall.)

glib/garray.c

@@ -2261,6 +2261,10 @@ g_byte_array_steal (GByteArray *array,
  * Create byte array containing the data. The data will be owned by the array
  * and will be freed with g_free(), i.e. it could be allocated using g_strdup().
  *
+ * Do not use it if @len is greater than %G_MAXUINT. #GByteArray
+ * stores the length of its data in #guint, which may be shorter than
+ * #gsize.
+ *
  * Since: 2.32
  *
  * Returns: (transfer full): a new #GByteArray
@@ -2272,6 +2276,8 @@ g_byte_array_new_take (guint8 *data,
   GByteArray *array;
   GRealArray *real;
 
+  g_return_val_if_fail (len <= G_MAXUINT, NULL);
+
   array = g_byte_array_new ();
   real = (GRealArray *)array;
   g_assert (real->data == NULL);