Errors related to _NET_WM_ICON are found in wm spec

[PCMan]

http://standards.freedesktop.org/wm-spec/wm-spec-1.4.html#id2552223
This is mainly a 32-bit / 64-bit issue.

The original spec:
_NET_WM_ICON
_NET_WM_ICON CARDINAL[][2+n]/32

This is an array of possible icons for the client. This specification
does not stipulate what size these icons should be, but individual
desktop environments or toolkits may do so. The Window Manager MAY
scale any of these icons to an appropriate size.

This is an array of 32bit packed CARDINAL ARGB with high byte being A,
low byte being B. The first two cardinals are width, height. Data is
in rows, left to right and top to bottom.

The proposed revision:
_NET_WM_ICON
_NET_WM_ICON CARDINAL[][2+n]/32(or 64 if you are on 64-bit systems)

This is an array of possible icons for the client. This specification
does not stipulate what size these icons should be, but individual
desktop environments or toolkits may do so. The Window Manager MAY
scale any of these icons to an appropriate size.

This is an array of unsigned long integers (usually 32 bit, and could
be 64-bit on 64-bit systems). Each element of the array contains a
32bit packed CARDINAL ARGB with high byte being A, low byte being B.
The first two cardinals are width, height. Data is in rows, left to
right and top to bottom.