This is modeled after the comment/uncomment code.  Each line's
individual indent is saved in the string array of the undo
group structure.

This fixes http://savannah.gnu.org/bugs/?46860.

The function does not contain any comment-specific code, so it can
be used to handle any kind of multiline undo item.

Also, extend the undo group structure to contain an array of strings,
one for each line in the group.  When indent/unindent is hooked up to
the undo/redo code, this will allow the latter to restore the exact
original indents.

And use these constants in another context too.

This also fixes https://savannah.gnu.org/bugs/?51735

.
Reported-by: Urja Rannikko <urjaman@gmail.com>
Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@telfort.nl>

The new option 'set selectedcolor' applies to marked text, to the
currently selected file in the file browser, and to the highlighted
match during interactive search-and-replace.

For some reason, when returning from suspension, SLang will produce
either a clipped error code (0xFF instead of 0xFFFF, when returning
from an externally induced suspension), or it will clip the code of
first subsequent keystroke to a single byte (when returning from a
normal, in-editor suspension: ^Z).

Side-step this by ignoring the clipped error code, and by using an
undefined control code as the first fake keystroke.  Ignoring the
clipped error code is not possible when using a single-byte locale,
otherwise the user would not be able to type the character with
code 0xFF (although it could still be entered with Esc Esc 255).

This fixes https://savannah.gnu.org/bugs/?51477.

Well, it will compile even without that include.  :|
I don't know why, since it does use va_list.

Extend get_softwrap_breakpoint() to break softwrapped lines on
whitespace when a flag is set.  This flag is controlled by the new
rcfile option "atblanks".  The '>' characters marking two-column
characters at the edge of the screen are disabled when it's on.

If get_softwrap_breakpoint() can't find whitespace in screen range, it
will break the line on the screen edge.  (In this case, a blank can be
on the last column of the screen, but text can't, so that a blank on the
last column doesn't become invisible and possibly break the display.)

This fulfills https://savannah.gnu.org/bugs/index.php?49959

.
Requested-by: Nicholas Boel <axxisd@gmail.com>

When the active syntax contains a comment command that specifies the
empty string, this should override the default comment of "#" and
should disable the Meta-3 keystroke.

To achieve this, the comment string is now set by default to "#" for
all syntaxes, so that it will be set when no comment command is given
(including for the "none" syntax), and is unset only by explicitly
specifying «comment ""» in a syntax file.

This fixes https://savannah.gnu.org/bugs/?51355

.
Reported-by: David Lawrence Ramsey <pooka109@gmail.com>

In the tiny version, Ctrl+Left and Ctrl+Right are available only
in the editor itself and in the file browser.

This fixes https://savannah.gnu.org/bugs/?51173.

Also, allow rebinding the word and block jumping functions
in the tiny version when nanorc files are reenabled.

Also, trim some comments and avoid an unused-variable warning.

And in the process transform the token DISABLE_HELP to ENABLE_HELP.

Allow the user to search in a help text with ^W and M-W.

Achieve this by not writing the help text directly to the screen
but first writing it to a temporary file and then opening this file
in a new buffer, and treating it specially: the normal file-reading
feedback is suppressed, the titlebar shows the headline of the text,
the cursor is hidden, and the menu is limited to just the up and down
movements and searching.

This fulfills https://savannah.gnu.org/bugs/?28994

.
Signed-off-by: Rishabh Dave <rishabhddave@gmail.com>

The interval 2013-2017 for the Free Software Foundation is valid
because in those years there were releases with changes by either
Chris or David, and the GNU maintainers guide advises to mention
a new year in all files of a package, not just in the ones that
actually changed, and be done with it for the rest of the year.

On some terminal emulators, Ctrl+Home and Ctrl+End produce special
keycodes, distinct from plain Home and End.  Make the users of those
emulators (and of the Linux console) glad by making ^Home and ^End
do the obvious thing, and the combinations with Shift too.

Verify at startup that the number is not too small.

We want to be able to scroll the line at edittop partially off the
screen.  For this to be possible, the new variable firstcolumn stores
the starting column of the viewport -- the starting column in the line
that edittop points to.

Since firstcolumn is used by go_back_chunks() and go_forward_chunks(),
it can't be completely #ifdefed out when NANO_TINY is set, but outside
of softwrap mode it should always be zero.

Currently firstcolumn is initialized to zero, reset to zero when
toggling softwrap mode off, and reset to zero when switching buffers
while softwrap mode is off.  It's otherwise unused, but its uses are
forthcoming.

This addresses a followup of https://savannah.gnu.org/bugs/?50362

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

Since gnulib provides these now, we can assume them.

The gnulib imports handle this for us now.

Now that we pull in the gnulib regex module, we can assume it exists.

Switch over to gnulib for these.

Switch over to gnulib for these.

These are provided by gnulib now.

The lines that come after an unpaired start have to know about this.

This fixes https://savannah.gnu.org/bugs/?50293.

(The variable 'pletion_line' is not conditionalized with this option, as
it would become messy.  The compiler will probably be able to elide it.)

When using --enable-tiny, it is not possible to use --enable-wordcomp,
because the word completion function uses the undo system.

Executing the 'complete_a_word' function will search from the start
of the current buffer for entire words that begin with the fragment
that is before the cursor, and will complete this fragment to the
first word that is found.  Each consecutive call of 'complete_a_word'
will search for the next matching word and will complete the fragment
to that.  By default the function is bound to the ^] keystroke.
Signed-off-by: Sumedh Pendurkar <sumedh.pendurkar@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>

It can be activated with --linenumbers on the command line or with
'set linenumbers' in a nanorc file, and it can be toggled with M-#.
Signed-off-by: Faissal Bensefia <faissaloo@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>

This lets users of braille displays find the selected item immediately.

This fulfills a request by Enrico Mioso.
See https://lists.gnu.org/archive/html/nano-devel/2016-09/msg00025.html.