Add attachaside and gruvbox
Initial config
53a312fb — Hiltjo Posthuma 1 year, 2 months ago
restore SIGCHLD sighandler to default before spawning a program

From sigaction(2):
A child created via fork(2) inherits a copy of its parent's signal dispositions.
During an execve(2), the dispositions of handled signals are reset to the default;
the dispositions of ignored signals are left unchanged.

This refused to start directly some programs from configuring in config.h:

static Key keys[] = {
	MODKEY,                       XK_o,      spawn,          {.v = cmd } },

Some reported programs that didn't start were: mpv, anki, dmenu_extended.

Reported by pfx.
Initial patch suggestion by Storkman.
config.mk: update to _XOPEN_SOURCE=700L

SA_NOCLDWAIT is marked as XSI in the posix spec [0] and FreeBSD and NetBSD
seems to more be strict about the feature test macro [1].

so update the macro to use _XOPEN_SOURCE=700L instead, which is equivalent to
_POSIX_C_SOURCE=200809L except that it also unlocks the X/Open System

[0]: https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/signal.h.html#tag_13_42
[1]: https://lists.suckless.org/dev/2302/35111.html

Tested on:
* NetBSD 9.3 (fixed).
* FreeBSD 13 (fixed).
* Void Linux musl.
* Void Linux glibc.
* OpenBSD 7.2 (stable).
* Slackware 11.

Reported-by: beastie <pufferfish@riseup.net>
Use sigaction(SA_NOCLDWAIT) for SIGCHLD handling

signal() semantics are pretty unclearly specified. For example, depending on OS
kernel and libc, the handler may be returned to SIG_DFL (hence the inner call
to read the signal handler). Moving to sigaction() means the behaviour is
consistently defined.

Using SA_NOCLDWAIT also allows us to avoid calling the non-reentrant function
die() in the handler.

Some addditional notes for archival purposes:

* NRK pointed out errno of waitpid could also theoretically get clobbered.
* The original patch was iterated on and modified by NRK and Hiltjo:
  * SIG_DFL was changed to SIG_IGN, this is required, atleast on older systems
    such as tested on Slackware 11.
  * signals are not blocked using sigprocmask, because in theory it would
    briefly for example also ignore a SIGTERM signal. It is OK if waitpid() is (in
    theory interrupted).

POSIX reference:
"Consequences of Process Termination":
grabkeys: Avoid missing events when a keysym maps to multiple keycodes

It's not uncommon for one keysym to map to multiple keycodes. For
example, the "play" button on my keyboard sends keycode 172, but my
bluetooth headphones send keycode 208, both of which map back to

    % xmodmap -pke | grep XF86AudioPlay
    keycode 172 = XF86AudioPlay XF86AudioPause XF86AudioPlay XF86AudioPause
    keycode 208 = XF86AudioPlay NoSymbol XF86AudioPlay
    keycode 215 = XF86AudioPlay NoSymbol XF86AudioPlay

This is a problem because the current code only grabs a single one of
these keycodes, which means that events for any other keycode also
mapping to the bound keysym will not be handled by dwm. In my case, this
means that binding XF86AudioPlay does the right thing and correctly
handles my keyboard's keys, but does nothing on my headphones. I'm not
the only person affected by this, there are other reports[0].

In order to fix this, we look at the mappings between keycodes and
keysyms at grabkeys() time and pick out all matching keycodes rather
than just the first one. The keypress() side of this doesn't need any
changes because the keycode gets converted back to a canonical keysym
before any action is taken.

0: https://github.com/cdown/dwm/issues/11
77e76dc5 — Hiltjo Posthuma 1 year, 7 months ago
Revert "Remove dmenumon variable"

This reverts commit c2b748e7931e5f28984efc236f9b1a212dbc65e8.

Revert back this change. It seems to not be an edge-case anymore since
multiple users have asked about this new behaviour now.
c7c260a2 — Hiltjo Posthuma 1 year, 8 months ago
bump version to 6.4
7dd9753a — Hiltjo Posthuma 1 year, 8 months ago
remove workaround for a crash with color emojis on some systems, now fixed in libXft 2.3.5

Remove dmenumon variable

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

There used to be a nodmenu patch that provided these changes:

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).
config.def.h: make keys and buttons const

pretty much all other variables are declared as const when they're not
Remove blw variable in favour of calculating the value when needed

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.
Make floating windows spawn within the monitor's window area

This is a follow-up on this thread:

The orginal code had constraints such that if a window's starting
attributes (position and size) were to place the window outside of
the edges of the monitor, then the window would be moved into view
at the closest monitor edge.

There was an exception to this where if a top bar is used then the
window should not obscure the bar if present, which meant to place
the window within the window area instead.

The proposed change here makes it the general rule that floating
windows should spawn within the window area rather than within the
monitor area. This makes it simple and consistent with no
exceptions and it makes the intention of the code clear.

This has the benefit of making the behaviour consistent regardless
of whether the user is using a top bar or a bottom bar.

Additionally this will have an effect on patches that modify the
size of the window area. For example if the insets patch is used to
reserve space on the left hand side of the monitor for a dock or a
vertical bar then new floating clients will not obscure that area.
Simplify client y-offset correction

The reasoning behind the original line may be lost to time as
it does not make much sense checking the position on the x-axis
to determine how to position the client on the y-axis.

In the context of multi-monitor setups the monitor y position
(m->my) may be greater than 0 (say 500), in which case the window
could be placed out of view if:
   - the window attributes have a 0 value for the y position and
   - we end up using the y position of bh (e.g. 22)

If the aim is to avoid a new floating client covering the bar then
restricting y position to be at least that of the window area
(m->wy) should cover the two cases of using a top bar and using a
bottom bar.
10fa5a58 — Hiltjo Posthuma 1 year, 10 months ago
sync code-style patch from libsl
code-style: simplify some checks

main change here is making the `zoom()` logic saner. the rest of the
changes are just small stuff which accumulated on my local branch.

pop() must not be called with NULL. and `zoom()` achieves this, but in a
very (unnecessarily) complicated way:

if c == NULL then nexttiled() will return NULL as well, so we enter this

	if (c == nexttiled(selmon->clients))

in here the !c check fails and the function returns before calling pop()

		if (!c || !(c = nexttiled(c->next)))

however, none of this was needed. we can simply return early if c was NULL.
Also `c` is set to `selmon->sel` so we can use `c` in the first check
instead which makes things shorter.
3a7e46ec — explosion-mental 1 year, 10 months ago
spawn: reduce 2 lines, change fprintf() + perror() + exit() to die("... :")

when calling die and the last character of the string corresponds to
':', die() will call perror(). See util.c

unmanage: stop listening for events for unmanaged windows

This is in particular to avoid flickering in dwm (and high CPU usage)
when hovering the mouse over a tabbed window that was previously
managed by dwm.

Consider the following two scenarios:


We start tabbed (window 0xc000003), tabbed is managed by the
window manager.
We start st being embedded into tabbed.

$ st -w 0xc000003

What happens here is that:
   - tabbed gets a MapRequest for the st window
   - tabbed reparents the st window
   - tabbed will receive X events for the window

The window manager will have no awareness of the st window and the
X server will not send X events to the window manager relating to
the st window.

There is no flickering or any other issues relating to focus.


We start tabbed (window 0xc000003), tabbed is managed by the
window manager.
We start st as normal (window 0xd400005).

What happens here is that:
   - the window manager gets a MapRequest for the st window
   - dwm manages the st window as a normal client
   - dwm will receive X events for the window

Now we use xdotool to trigger a reparenting of the st window into

$ xdotool windowreparent 0xd400005 0xc000003

What happens here is that:
   - tabbed gets a MapRequest for the st window
   - tabbed reparents the st window
   - the window manager gets an UnmapNotify
   - the window manager no longer manages the st window
   - both the window manager and tabbed will receive X events
     for the st window

In dwm move the mouse cursor over the tabbed window.

What happens now is that:
   - dwm will receive a FocusIn event for the tabbed window
   - dwm will set input focus for the tabbed window
   - tabbed will receive a FocusIn event for the main window
   - tabbed will give focus to the window on the currently selected
   - which again triggers a FocusIn event which dwm receives
   - dwm determines that the window that the FocusIn event is for
     (0xd400005) is not the currently selected client (tabbed)
   - dwm sets input focus for the tabbed window
   - this causes an infinite loop as long as the mouse cursor hovers
     the tabbed window, resulting in flickering and high CPU usage

The fix here is to tell the X server that we are no longer interested
in receiving events for this window when the window manager stops
managing the window.
ee677c14 — Hiltjo Posthuma 1 year, 10 months ago
Revert "do not call signal-unsafe function inside sighanlder"

This reverts commit 6613d9f9a1a5630bab30bc2b70bdc793977073ee.

Discussed on the mailinglist:
do not call signal-unsafe function inside sighanlder

die() calls vprintf, fputc and exit; none of these are
async-signal-safe, see `man 7 signal-safety`.