Straightforward code is more important than the tiniest possible binary.

Also adjust some comments and rename a variable.

For horizontal scrolling, it is not the /desired/ column position that
is relevant for determining whether a line needs to be redrawn after a
cursor movement, but the /actual/ column positions before and after.

This fixes https://savannah.gnu.org/bugs/?48627,
and fixes https://savannah.gnu.org/bugs/?48629.

Having two unneeded parameters in the tiny version is acceptable --
the code gets so much more readable.

Leave the rest of any escape sequence to be processed normally, which
should be possible because those characters are all in ASCII range.

This fixes https://savannah.gnu.org/bugs/?48318.

There is no need to specially flag a function key or editing key --
the keycode is indication enough in itself: outside of byte range.

And instead of using two key types, just use a bool to indicate whether
a keystroke involves Meta.

A keycode is either already in byte range (so there is nothing to do)
or it is not and it shouldn't be (so there is nothing to do either).

After initialization, the type of a key is never used nor needed
(other than for meta keys).

Those lines don't exist in that mode -- the relevant subwindows are
smaller, or have been made smaller just before.

This fulfills https://savannah.gnu.org/bugs/?48154.

And hard-bind the keys Ctrl+Up and Ctrl+Down to these functions.

Unlike the paragraph-jumping code, these new functions disregard
any indentation, treating only blank lines as separators.  They
also do an automatic smart home when that option is set.

This fulfills https://savannah.gnu.org/bugs/?48291.

This allows the user to specify which other characters, besides the
default alphanumeric ones, should be considered as part of a word, so
that word operations like Ctrl+Left and Ctrl+Right will pass them by.

Using this option overrides the option --wordbounds.

This fulfills https://savannah.gnu.org/bugs/?47283.

When we get a ^J as verbatim input, it is not possible to include it
into the file buffer or the prompt answer, because this would mean
adding an encoded null to the buffer or answer, and that is not what
the user intended.  One option would have been to simply ignore a ^J
in verbatim input.  But the choice has been made to act the same way
as when the ^J (0x0A) is found in the file data: start a new line.

That is the same response as to the Enter key, yes -- but the code
for the Enter key is ^M (0x0D), not ^J.  So, to be more precise,
rename the relevant variable from 'got_enter' to 'got_newline'.

Use knowledge of UTF-8 instead of converting to wide characters first.

Any control character is represented by a ^ plus an ASCII character.

Instead of showing the upper control codes like this:

   ^À ^Á ^Â ^Ã ^Ä ^Å ^Æ ^Ç ^È ^É ^Ê ^Ë ^Ì ^Í ^Î ^Ï
   ^Ð ^Ñ ^Ò ^Ó ^Ô ^Õ ^Ö ^× ^Ø ^Ù ^Ú ^Û ^Ü ^Ý ^Þ ^ß

show them like this:

   ^` ^a ^b ^c ^d ^e ^f ^g ^h ^i ^j ^k ^l ^m ^n ^o
   ^p ^q ^r ^s ^t ^u ^v ^w ^x ^y ^z ^{ ^| ^} ^~ ^=

The lower control codes continue to be shown like this:

   ^@ ^A ^B ^C ^D ^E ^F ^G ^H ^I ^J ^K ^L ^M ^N ^O
   ^P ^Q ^R ^S ^T ^U ^V ^W ^X ^Y ^Z ^[ ^\ ^] ^^ ^_

The representation of DEL (0x7F) continues as ^?.

Further, use knowledge of UTF-8 to avoid a roundtrip through
wide characters.

By moving the test for the only situation where do_comment() does nothing
(when only the magic line is selected) further up front, the add_undo()
can be called before the commenting/uncommenting starts and two variables
and an extra function are made unnecessary.

Store the file sizes from before and after the commenting/uncommenting
in the undo struct, so they can be restored when undoing or redoing.

This fixes https://savannah.gnu.org/bugs/?48062

.
Signed-off-by: Mike Scalora <mike@scalora.org>

This allows for commenting or uncommenting a line or a bunch of lines
with a single keystroke (default binding: M-3).  The characters used
for commenting/uncommenting are specified by the active syntax file.
Reviewed-by: Benno Schulenberg <bensberg@justemail.net>
Signed-off-by: Mike Scalora <mike@scalora.org>

Signed-off-by: Rishabh Dave <rishabhddave@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>

Error messages about lock files should not get overwritten by purely
informational messages, only by alerting ones.

This fixes https://savannah.gnu.org/bugs/?47963.

The general mechanism for not allowing important messages to be overwritten
will take care of not overwriting warnings about failed file lockings.

If during startup there are multiple error messages, currently only the
last one remains and can be read.  To improve on that, introduce a short
pause between error messages -- even if it's not enough to read them all,
at least the user will be aware that there are multiple ones.

This also causes a few error messages to beep that currently don't beep,
such as when a file is unwritable.

When verifying that a match is a separate word (during spell checking),
instead of first copying out the word, then passing the word, and then
measuring its length, just pass its length straigtaway.

When we're spell checking, we don't need a special mechanism to detect
we have come full circle: reaching the end-of-buffer means we're done.
So don't bother to reset came_full_circle when we're spell checking
(when begin == NULL) but simply ignore its value.

Add a global variable, 'present_path', so that 'cwd_tab_completion()'
knows where the user is in the browser, so that it can try completions
against names in that directory instead of always against names in the
current working directory (where nano was invoked).

This fixes https://savannah.gnu.org/bugs/?47234

.
Signed-off-by: Rishabh Dave <rishabhddave@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>

This restores things to the way they were before commit 36ec76a5.
Apparently all those refreshes are needed in some cases after all.

For a little contrast with the function edit_refresh() -- it's
annoying that when you search for the latter you get to see all
the settings of the flag too.