Many users new to dwm find themselves caught out by being kicked out to the login manager (dwm crashing) when they open 50+ clients for demonstration purposes. The number of clients reported varies depending on the resolution of the monitor.

The cause of this is due to how the default tile layout calculates the height of the next client based on the position of the previous client. Because clients have a minimum size the (ty) position can exceed that of the window height, resulting in (m->wh - ty) becoming negative. The negative height stored as an unsigned int results in a very large height ultimately resulting in dwm crashing.

This patch adds safeguards to prevent the ty and my positions from exceeding that of the window height.

This jarred me a bit while reading the code, since "sw" usually refers
to the global screen geometry, but in drawbar() only it refers to
text-related geometry. Renaming it makes it more obvious that these are
not related.

No functional changes, but for every other function we have a forward
declaration here. getatomprop should be no exception.

There are two places that mfact can be set:

- In the mfact global, which is defined at compile time and passed
  into m->mfact during monitor setup. No bounds checks are performed,
  but the comment alongside it says that valid values are [0.05..0.95]:

      static const float mfact = 0.55; /* factor of master area size [0.05..0.95] */

- By setmfact, which adjusts m->mfact at runtime. It also does some
  minimum and maximum bounds checks, allowing [0.1..0.9]. Values outside
  of that range are ignored, and mfact is not adjusted.

These different thresholds mean that one cannot setmfact 0.95 or 0.05,
despite the comment above that lists the legal range for mfact.

Clarify this by enforcing the same bounds in setmfact at runtime as
those listed for mfact at compile time.

In dwm.c function declarations are in alphabetical order except for
updategeom(). There doesn't appear to be any reason for this, so this
patch corrects that, and now all function declarations are in
alphabetical order.

Reported by Kernc, thanks!

"This makes a particular program that uses libwnck [1] fail after:

    Wnck-WARNING **: Property _NET_WM_NAME contained invalid UTF-8

in this code [2] because the returned string contains a '\0' and the
documentation for g_utf8_validate() [3] explicitly states that when
string length is provided, no nul bytes are allowed."

It is not entirely clear it is incorrect, other WM's seem to not
NUL terminate it either though.

This is useful for configuring compositors to ignore the status bar
window.

The previous patches introduced some unclean space-based indentation
patterns. This patch fixes them.

This also fixes a bug where client windows only switch to floating mode when the
mouse is dragged in one specific direction.

Before this change it is not possible to press a button in a client on the first
click if the client is not yet focused. The first click on the button would
only focus the client and a second click on the button is needed to activate it.
This situation can occur when moving the mouse over a client (therefore focusing
it) and then moving the focus to another client with keyboard shortcuts.

After this commit the behavior is fixed and button presses on unfocused clients
are passed to the client correctly.

- unify multi-line expression alignment style.
- unify multi-line function call alignment style.
- simplify client moving on monitor count decrease.
- clarify comment for focusin().
- remove old confusing comment about input focus fix in focusmon(). The
  explanation is already in the old commit message, so no need to keep it in the
  code.
- remove old comment describing even older state of the code in focus().
- unify comment style.
- break up some long lines.
- fix some typos and grammar.

- better scaling for occupied tag squares.
- draw statusline first to omitt some complicated calculations.

Configuring geometry before applying rules makes it possible to have
more complex constraints in applyrules that depend on the initial window
dimensions and location.

patch provided by Bert Münnich <ber.t_AT_posteo.de>, thanks!

True, False are X11-specific (int), make sure to use c99 stdbool for
program-specific things.

Some clients try to set _NET_WM_STATE_FULLSCREEN even when the window is
already in fullscreen.
For example, c->oldstate was set two times in a raw and window would
then always be floating.
We must check that it's not the case before processing it.
(original patch modified with suggestion from Markus Teich
<markus.teich@stusta.mhn.de>)

important:
- drw_rect: didn't use w and h, change the dwm code accordingly.
- drw_text: text is NULL is not allowed, use drw_rect().

- signal: print error string.
- die: start message with lower-case (consistency).
- bump version to 2015.

"Limit the amount of updates when resizing or moving a window in floating
mode to 60 times per second. This makes resizing and moving alot smoother
and by limiting it it also uses alot less resources on my machine.

however renamed theme into scheme resp. Theme into ClrScheme