This fixes https://savannah.gnu.org/bugs/?49750.

Modern VTE-based terminals now produce codes for those keys and
no longer swallow them when nano is active.

This addresses https://savannah.gnu.org/bugs/?49746.

There is no need for that -- it just causes flicker.

This fixes https://savannah.gnu.org/bugs/?49742.

Only when doing replacements does the edit window need a refresh: for
every new spotlight.  So, do the update request in the latter routine.

(The previous commit fixed https://savannah.gnu.org/bugs/?49737.)

This fixes https://savannah.gnu.org/bugs/?48622.

For UTF-8 support under Slang, at least Slang 2.0 is needed.
And glib2 is also used for snprintf() if it's unavailable.

Achieve this by reusing the code that gives feedback when trying to
save a buffer while using --tempfile and the file has no name yet.

This fixes https://savannah.gnu.org/bugs/?48622.

Also for Delete, End, PageUp and PageDown (on some terminals)
the last byte in the sequence needs to be checked.

This fixes https://savannah.gnu.org/bugs/?49710.

Achieve this elegantly by factoring out the reading of one rcfile.

Also remove some unneeded prototypes, adjust some comments, and
move a constant definition to the top of the file.

Also improve or correct some comments.

If it would, the returned file descriptor would make nano crash,
because the corresponding stream has not been opened.  And when
returning zero instead (as the code did originally), nano would
open an empty buffer, although it claims to be reading the file.

In short: I think this is a leftover of an attempted fix of
https://savannah.gnu.org/bugs/?25297, from commit 2823c99e.

That is: when --rebindkeypad is in effect -- without this option
they were already getting distinguished.

Both would jump a word to the left -- now each jumps a word in the
proper direction.

This fixes https://savannah.gnu.org/bugs/?49636.

We should avoid defining color schemes that are unreadable on common
white-on-black or black-on-white terminals.  Change the black in the
autoconf error strings to brightred for that reason.

When probing symbols provided by ncurses, use the sublibs that pkg-config
reported in case they're needed (like when libtinfo is a sep library).

URL: https://savannah.gnu.org/bugs/?49614

In addition, tweak some of the wording.

Kind-of-discovered-by: Markus Bergholz <markuman@gmail.com>

Also when somehow key_defined() is missing.

This fixes https://savannah.gnu.org/bugs/?49614

.
Reported-by: Mike Frysinger <vapier@gentoo.org>

- make version highlight less blindly greedy and conform to real versions
- move version matching before USE matching to avoid hitting USE flags
  that look like versions
- change USE regex to match the Gentoo PMS
- extend arch match to include more keywords
- make category matching more restrictive to avoid false positives
- drop operators =< and => that Gentoo doesn't support

URL: https://savannah.gnu.org/bugs/?49569

Reported-by: Konstantin Shakhnov <kastian@mail.ru>

(Bug was introduced yesterday, by commit a4132e2e.)

Otherwise the user can override a 'set nowrap' in /etc/nanorc only
via the command line.

This fixes https://savannah.gnu.org/bugs/?49593 reported by Shirish.

This fixes the two bugs reported by Anton Minaev
in https://savannah.gnu.org/bugs/?49511.

This fixes https://savannah.gnu.org/bugs/?49530.

Also, don't use ignore-case for things that don't contain letters.

Also replace some backslashed spaces because they hinder the
justification of the man page.