Unset the "Modified" marker only at the point where the file was last
saved -- if there is such a point, because it can be missing when the
undo stack was discarded.

This fixes https://savannah.gnu.org/bugs/?52689

.
Reported-by: Liu Hao <lh_mouse@126.com>
Original-idea-by: Brand Huntsman <alpha@qzx.com>

When doing that, there is no need to save and restore the Modified
state when writing a marked region.

To get rid of two double negatives.

This fixes https://savannah.gnu.org/bugs/?52519.

This also means that no question needs to be asked when exiting.

This fixes https://savannah.gnu.org/bugs/?52504

.
Reported-by: Peter Passchier <peter@passchier.net>

Otherwise we would overwrite the current file with just the selection.

This fixes https://savannah.gnu.org/bugs/?52482.

The pointer not being NULL is enough indication that the mark is set.

Also, rename the pointer from 'mark_begin' to simply 'mark', since
the former is kind of pleonastic.

While doing that, move the affected function to the utils.c file
and tweak it a bit.

This fixes https://savannah.gnu.org/bugs/?52468.

This fixes https://savannah.gnu.org/bugs/?52392.

Also, properly refer to numreplaced as signed, since it's ssize_t
(even though it's only shown when positive).

In the tiny version, do_prompt() will now have an extra NULL
parameter, which will cost maybe twenty extra bytes of code.
That is acceptable when it saves thirty lines in the source.

The key sequence ^R ^X M-F <Enter> would cause nano to abort, because
it would try to add an empty string to a history list.  (Furthermore,
simply don't execute an empty command, because it is pointless.)
Reported-by: Marco Diego Aurélio Mesquita <marcodiegomesquita@gmail.com>

^S will be the first thing people will try for saving a file,
and ^Q is somewhat mnemonic because it is to the left of ^W:
it searches backward.

Make these keystrokes available also in the tiny version.

Before writing a file out, nano should check that the file on disk
hasn't been modified since it was read -- not only for the normal
"Write Out" action (^O), but also for "Save File" (future ^S) and
for "Save and Exit" (^X when --tempfile is used).

When writing fails and --tempfile is in effect, don't go on to prompt
for a file name; instead let the user decide what she wants to do.

This fixes https://savannah.gnu.org/bugs/?51040

.
Signed-off-by: Viorel Bota <botaviorel@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@telfort.nl>

This fixes https://savannah.gnu.org/bugs/?52060

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

Signed-off-by: Marco Diego Aurélio Mesquita <marcodiegomesquita@gmail.com>

Signed-off-by: Marco Diego Aurélio Mesquita <marcodiegomesquita@gmail.com>

When multiple files were open and [x/n] was being shown in the title
bar, don't show nano's name and version number when just one buffer
remains open, but show [1/1] instead.  It is less surprising.

When multiple buffers are open, replace nano's name and version number
with an indication how many buffers are open preceded by the sequence
number of the current buffer.
Signed-off-by: Marco Diego Aurélio Mesquita <marcodiegomesquita@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@telfort.nl>

And use these constants in another context too.

Also rename a variable, to match the saving routine.