errx() already appends \n internally. "\n" in the error message will
result in a blank line after the message.

Use the XComposite extension to get the composite overlay window,
instead of just using the normal root window. This ensures that
composited windows are covered.

This time, we hide it behind a config option because it might break
things more than it fixes.

fixes #184

This adds some feedback to a keypress which previously had no visible effect.

While the text “no input” isn’t the most descriptive, it was the only one I
could think of which fit into the unlock indicator circle. If you have a better
suggestion, let me know.

fixes #164

This was largely copied from the i3 configure.ac and Makefile.am.

The code now tries the following options, in order:

• obtain monitors via RandR 1.5
• obtain outputs via RandR ≤ 1.4
• obtain screens via Xinerama

fixes #159
related to #101
related to #148
related to #149

When grabbing the pointer/keyboard fails, a new code path is activated, which:

1. Uses the standards-compliant _NET_ACTIVE_WINDOW root window property to
   determine the window to restore focus to.

2. Sets the input focus to the i3lock window, thereby possibly force-closing
   open context menus (works with e.g. Google Chrome, does not work with
   e.g. thunar, gedit).

3. Upon exiting, restores focus to the window from step ① by sending a
   _NET_ACTIVE_WINDOW ClientMessage to the root window. Note that this step
   requires https://github.com/i3/i3/pull/3027 in i3 to not mess up focus.

fixes https://github.com/i3/i3lock/issues/35

This is explained in the commit message here:
f468f0b243

Using 'optind' in getopt_long() shadows actual 'optind' being provided
by getopt, thus prevents any future options change from using optind.

See https://www.gnu.org/software/libc/manual/html_node/Getopt-Long-Options.html#index-getopt_005flong

Also apply two security measures for OpenBSD:
- use explicit_bzero(3)
- mlock(2) works for non-root users too

there is nothing PAM-specific about pam_state or pam_state_t. therefore
rename them to be authenticator independant.

Display "locking…" message when grabbing the pointer/keyboard,
after at least 250 ms of unfruitful attempts. If grabbing
eventually fails, application will not fork and return 1.

This will make i3 unlock automatically after authentication failure and
correct input without pressing <Enter> again after the "wrong"-indicator
is gone.

* Removed obsolete inactivity timeout

Not sure why travis didn’t warn about this on the PR. The only reference
to the PR I can find is https://travis-ci.org/i3/i3lock/builds/130470377

Add support for `xss-lock --transfer-sleep-lock'

fixes #71

fixes #51

fixes #50

It has not been in use since commit 7eb43aeabd

fixes #43

fixes #32

fixes #12

The script used to make these changes can be found at:

   https://gist.github.com/Deiz/32322020f76d23e2bf8f

When the unlock indicator warns the user that a password was typed
wrong, it now also reports the state of the capslock and numlock
modifiers.

Signed-off-by: Alexandre Boeglin <alex@boeglin.org>

From here on, we’ll use clang-format to automatically format the source.

This has worked well in i3, so we are introducing it for i3lock.

This is the approach taken by libX11, and feels more consistent.

xkb_context is guaranteed to be initializated from load_keymap.

This add a protection against wrong password spamming