Description:
------------
If either dimension of an image passed to imagescale() is greater
than or equal to 0x1000000‬, the image cannot be scaled, but still
gdImageScale() of the *bundled* libgd would return a (blank)
image.  This issue is fixed in upstream libgd as of 2.2.3.

Note that the reproduce script given below requires an appropriate
fix for bug #77269 regarding bundled libgd (otherwise we likely
hit a segfault), and a master build of upstream libgd (otherwise
the original image couldn't be allocated in the first place[1]).

[1] <https://github.com/libgd/libgd/commit/c3cf674cb444696a36f720f785878b41225af063>

Test script:
---------------
<?php
$img = imagecreate(2**28, 1);
var_dump(imagescale($img, 1, 1, IMG_TRIANGLE));


Expected result:
----------------
Warning: imagescale(): gd warning: product of memory allocation multiplication would exceed INT_MAX, failing operation gracefully
 in %s on line %d
bool(false)


Actual result:
--------------
Warning: imagescale(): gd warning: product of memory allocation multiplication would exceed INT_MAX, failing operation gracefully
 in %s on line %d
resource(%d) of type (gd)