Ticket #3111: configurable selection reset on CK_Store.

In mc-4.7.x.x selection was reset on CK_Store (copy to buffer).
In mc-4.8.x (4.8.11 and older) it is not.

Now this behavior is configurable using editor_drop_selection_on_copy
key in the ini file.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '3111_mcedit_reset_selection'

* 3111_mcedit_reset_selection:
  Ticket #3111: configurable selection reset on CK_Store.
Ticket #3093: keep symlinks in cwd at startup.

If you navigate in your shell to a directory containing symlinks and
then start mc, mc will show the canonical path instead. It would be nice
to make it show the directory with the symlinks.

Example: in your shell execute these:

user:~$ mkdir -p /tmp/a/b /tmp/x ; ln -s /tmp/a/b /tmp/x/y
user:~$ cd /tmp/x/y
user:/tmp/x/y$ mc

In mc you'll find yourself in /tmp/a/b, though it'd be nicer to see
/tmp/x/y at the top, and correspondingly navigating to the parent would
take you to /tmp/x.

If you start bash or zsh from /tmp/x/y, the new instance will start
displaying the working directory as such. They do this via the PWD env
variable. On one hand, they set and maintain PWD to point to the current
directory, using the path as specified by the user (possibly containing
symbolic links). On the other hand, they check its value at startup. If
$PWD points to the same physical directory as the actual working
directory then they use this value. If $PWD points somewhere else then
it's simply ignored (so it's a hint only as to which symlinks to use to
get to the working directory, but never alters the actual cwd).

Now mc also does the same at startup (with respect of "Cd follows
links" option). Relative directories specified in the command line  are
applied after possibly replacing the canonical cwd with $PWD. This way
for example

user:/tmp/x/y$ mc . ..

opens two panels in /tmp/x/y and /tmp/x instead of /tmp/a/b and /tmp/a
(whereas /tmp/x is actually a different directory than /tmp/a).

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Add tests for check that symlinks in cwd are handled correctly.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>
Merge branch '3093_keep_symlink_cwd_startup'

* 3093_keep_symlink_cwd_startup:
  Add tests for check that symlinks in cwd are handled correctly.
  Ticket #3093: keep symlinks in cwd at startup.
(load_setup): clarify usage of internal variable.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Ticket #3124: really escape Zsh history

Per Zsh documentation last command prefixed with space lingers in the
internal history until the next command is entered before it vanishes.
To make it vanish right away, type a space and press return.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '3124_zsh_escape_history'

* 3124_zsh_escape_history:
  Ticket #3124: really escape Zsh history
Ticket #3125: don't override precmd on Zsh

Do not override global precmd() funcation on Zsh. Define new _mc_precmd()
function and add it to precmd_functions array instead. This also effectively
fixes race condition with pwd call on Zsh, which may lead to empty prompt in mc.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '3125_zsh_precmd'

* 3125_zsh_precmd:
  Ticket #3125: don't override precmd on Zsh
Ticket #3093: fix sefault in case of run "mcedit relative/path/to/file".

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '3093_keep_symlink_cwd_startup_fix'

* 3093_keep_symlink_cwd_startup_fix:
  Ticket #3093: fix sefault in case of run "mcedit relative/path/to/file".
src/subshell.c: indentation.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Ticket #2290: make file find faster.

Gets rid of get_line_at() function that was called only at one place and
was tightly coupled with caller function. It allows to perform some
minor optimizations, and as a result improve search time by 8%.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Optimize updates of status bar during search.

Optimization is based on examining file size and time of the last status
update. This is synchronous and is based on assumption that relatively
small files are quickly processed even on slow hardware so if refresh
timeout expires during their processing, the delay couldn't be noticed
by human. Therefore only rather big files have to be reported
unconditionally, and others - only if there is a match in this file or
if timeout expires.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Refactoring of WListbox widget.

Use GQueue instead of GList to store listbox entries.

g_list_append() function is slow because it uses g_list_last()
internally to traverse from the beginning to the end of a list, so
forming a list of results has O(n*n) complexity instead of O(n).
GQueue contains pointers to head and tail of list and list length.
So in this case we don't need seach end of list every time when we
want append listbox entry to the listbox.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '2290_find_file_speedup'

* 2290_find_file_speedup:
  Refactoring of WListbox widget.
  Optimize updates of status bar during search.
  Ticket #2290: make file find faster.
Ticket #3117: Launching editor with CK_Edit shouldn't pass line number.

When pressing F4 to start the editor, a "+1" argument is passed to open
the file at the first line.

For some editor this is absolutely unnecessary since they open the file
there anyways. For some others (at least "joe", but probably others too)
this is harmful: joe has a convenience feature that by default it opens
the file where it was last open, unless of course overridden from
command line. Currently mc forces joe to open the file at the first
line, although opening it where it was last open would be much more
desired.

The right solution would be to consult mc.lib only when opening the
viewer/editor through the "word search in files (M-?)" feature, and
not when F3/F4 is pressed on a file, in the latter case $VIEWER or
$EDITOR should simply be launched with the filename but no additional
parameters.

Initial step: minor refactoring:
(do_edit_at_line): rename to edit_file_at_line.
(edit_file_at_line): changed type of arguments from int to gboolean.
(view_file_at_line): likewise.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Allow launch external editor/viewer w/o line number.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Launching external editor/viewer with F4/F3 w/o passing line number.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>