Use dup() instead to get an available file descriptor to avoid hijacking
already existing descriptor.

Fixes #1709

It's a reoccurring issue that users try to build individual components
by pointing cmake at a specific subdirectory, e.g. 'cmake vncviewer'.
CMake, unfortunately, has insufficient protection against this so we'll
need to add a manual check.

This commit only adds it to the most likely places for misuse so we
don't have to pollute every CMakeLists.txt.

Some of the flags have been removed and we don't need to consider 32-bit
libraries anymore.

It seems this folder is created when building the vncviewer, which has
to be built before the server.

All the information we need is now available in keysymdef.h, so let's
get everything updated and in sync.

Make it easier to see what's code and what's just a lot of data.

This is a manually set up table specific for TigerVNC. For clarity,
separate it out from the general keysym/Unicode table.

Otherwise it will log that we chose the (invalid) type 0.

Most compilers currently accept arbitrary identifiers in this place
and ignore then, but this is going to change and turn into an error.
(It prevents compilers from diagnosing misspelled type names,
and the resulting declaration is not a prototype, so no type
errors will be reported at call sites.)

Option is -D, which is what sshd uses for the same option.

Also add description of the new option to the vncsession
man page.

Tested on Void Linux using the new option, also tested on
Fedora without using the new option.

Resolves #1649

This change makes the ZRLEEncoder respect a client's desired
compressionLevel. The ZlibLevel option is marked deprecated and removed
from the manpages.

This make sure we have any new defines, in case we want to use them.

This is mainly a copy of XKeysymToString() from libX11. We've also added
a wrapper that still gives a string, even if there is no name for the
requested keysym.

This grows the binaries a bit, but not with any extreme amount so is
hopefully worth it to get better debug logging.

Clarify how to build server out-of-tree

We user the real, not the effective user ID, to check if the user is
allowed to log in with the "Plain" security types. Otherwise it would be
necessary to log in as root when Xvnc is installed with the set-user-id
bit on.

Signed-off-by: Carlos Santos <casantos@redhat.com>

This permits to enable PAM for the effective user of the Xvnc process by
adding this to ~/.vnc/config or /etc/tigervnc/vncserver-config-defaults:

   SecurityTypes=TLSPlain
   PlainUsers=%u

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2233204
Signed-off-by: Carlos Santos <casantos@redhat.com>

Make sure we don't overlook missing accelerators in the translations
again.

They were unfortunately omitted here and there for some languages.

We can get races with clipboard managers in the server that is very
confusing to the user.

When the clipboard changes locally, we tell the server to drop the old
clipboard (as it is now lost). But we don't send over the new clipboard
until we get focus again, in order to not leak more data than necessary.
This causes some clibpoard managers to take over ownership in order to
avoid an empty clipboard. And this takes precedence over the new client
clipboard as it happened later. Effectively reverting the clipboard the
user sees.

Avoid all of this by simply ignoring the server when we don't have
focus. This is likely what users expect anyway as they expect their
currently focused application to control the clipboard, not vncviewer in
the background.

Don't assume a lack of TCP listeners means the server will be
unreachable. There might be other methods of access, so let the higher
levels do that sanity check instead.

This will not do the correct thing for Unix sockets.

It was a poor choice of words to call these keysyms "unknown" as they
are likely perfectly normal keysyms, they just cannot be found in the
currently loaded keyboard layout. This log message has confused users,
so let's get rid of the "unknown" part.

We already use the verb "add" heavily in the other log messages, so
let's keep that rather than switch to some for of "map".

Using "c" is in conflict the the "Ctrl" entry, so we need to pick
something else here.

This was a regression introduced in 44b085a.

FLTK only allows 256 different box types, but it doesn't actually check
this when registering new ones.

Move our custom types to a valid range, and add an assert for good
measure to make sure we don't overflow FLTK's internal structures.

Since the contents of the LINGUAS file affects which targets are
created, we must tell CMake to reconfigure things if this file changes.

These aren't supported in C2x, and clang will already now complain.

Update copyright year to 2023

Follow the colors that modern desktops use when it comes to background,
text and selections.

There is something broken with these FLTK draw routines on Windows. They
leave gaps at the start and end of the arc/pie rather than filling the
whole specified span. So we need to nudge the numbers a bit to work
around this.