This reverts commit c2b748e793.
Revert back this change. It seems to not be an edge-case anymore since
multiple users have asked about this new behaviour now.
Reasoning: Since 2011 dmenu has been capable of working out which
monitor currently has focus in a Xinerama setup, making the use
of the -m flag more or less redundant.
This is easily demonstrated by using dmenu in any other window
manager.
There used to be a nodmenu patch that provided these changes:
https://git.suckless.org/sites/commit/ed68e3629de4ef2ca2d3f8893a79fb570b4c0cbc.html
but this was removed on the basis that it was very easy to work
out and apply manually if needed.
The proposal here is to remove this dependency from dwm. The
mechanism of the dmenumon variable could be provided via a patch
if need be.
The edge case scenario that dmenu does not handle on its own, and
the effect of removing this mechanism, is that if the user trigger
focusmon via keybindings to change focus to another monitor that
has no clients, then dmenu will open on the monitor containing the
window with input focus (or the monitor with the mouse cursor if
no windows have input focus).
If this edge case is important to cover then this can be addressed
by setting input focus to selmon->barwin in the focus function if
there is no client to give focus to (rather than giving focus back
to the root window).
The purpose and reasoning behind the bar layout width (blw) variable
in dwm the way it is today may not be immediately obvious.
The use of the variable makes more sense when looking at commit
2ce37bc from 2009 where blw was initialised in the setup function
and it represented the maximum of all available layout symbols.
for(blw = i = 0; LENGTH(layouts) > 1 && i < LENGTH(layouts); i++) {
w = TEXTW(layouts[i].symbol);
blw = MAX(blw, w);
}
As such the layout symbol back then was fixed in size and both drawbar
and buttonpress depended on this variable.
The the way the blw variable is set today in drawbar means that it
merely caches the size of the layout symbol for the last bar drawn.
While unlikely to happen in practice it is possible that the last bar
drawn is not that of the currently selected monitor, which can result
in misaligned button clicks if there is a difference in layout symbol
width between monitors.
