I'm using twm on a new installation of Centos6.3, with Firefox 18.0. When I iconise the Firefox window the resulting icon bitmap (as used in twm's icons) is a rather lar… (tuilleadh eolais)
I'm using twm on a new installation of Centos6.3, with Firefox 18.0. When I iconise the Firefox window the resulting icon bitmap (as used in twm's icons) is a rather large 256x256, rather than more usual sizes around the 16 to 32 mark.
I get the same effect with a remote session where twm is running on an older FC11 box but Firefox is running on the Centos one. In contrast, with Firefox 3.5.5 on the FC11 box the icon sizes are small as expected (and desired).
Investigating with xprop, I see that the _NET_WM_ICON(CARDINAL) property is set on the newer firefox and contains an entry for the 256x256 bitmap. It /seems/ like this bitmap is compiled in as renaming /usr/share/icons/hicolor/256x256/apps/firefox.png did not change the situation, and that was the only large firefox icon that I could find in the filesystem. Is there any way to tell firefox not to provide this large bitmap as a potential icon for the window manager?
EDIT: A satisfactory workaround in my case was to use ForceIcons as explained by AndrewA below. After inspecting the TWM source I found that the window name matching could be done on the WM_CLASS data as well as the name, so simply using "Firefox" as the string to match against works. Thanks again to AndrewA.