No double lines with ncurses

[mc-butler]

Important

This issue was migrated from Trac:

Origin	https://midnight-commander.org/ticket/3158
Reporter	egmont (@egmontkob)

Choose a skin with double lines, e.g. "mc -S double-lines". These are properly displayed with the slang build, but are replaced by brighter single lines with ncurses.

If the enrivonment suggests that double lines are most likely supported (TERM refers to a graphical emulator and locale is utf-8) then the characters defined in the skin file should be used without being altered in any way.

[mc-butler]

Changed by andrew_b (@aborodin) on Mar 13, 2014 at 4:33 UTC (comment 1)

Ticket #3182 has been marked as a duplicate of this ticket.

[mc-butler]

Changed by egmont (@egmontkob) on Mar 13, 2014 at 7:00 UTC (comment 2)

Please note that #3182 (closed as dupe) contains more info: It's not only the double lines that are not supported, but also other kinds of line drawing characters.

[mc-butler]

Changed by egmont (@egmontkob) on Mar 28, 2017 at 22:58 UTC (comment 3)

Ticket #3802 has been marked as a duplicate of this ticket.

[mc-butler]

Changed by zaytsev (@zyv) on Feb 22, 2025 at 12:04 UTC (comment 4)

• Blocked by set to #3264

[egmontkob]

10+ years after reporting it, let me try to fix it.

It's almost certainly not an ncurses bug; these double line characters do show up properly in the ncurses build in the panel listing (if a filename contains them), or in mcview.

NCURSES_NO_UTF8_ACS=1 or lack thereof doesn't make a difference.

[egmontkob]

mc-3158-ncurses-double-lines-draft1.patch

This seems to do it. At least the major part.

There are still some addch() calls in that file that aren't wide character friendly, also addstr() which I'm not sure about. So the work along these lines needs to continue a bit.

And then a lot of #ifs for ncurses vs. ncursesw, to make sure that it still compiles and runs with non-wide ncurses just as before.

[egmontkob]

mc-3158-ncurses-double-lines-draft2.patch

Much nicer than draft1. Still gotta check addstr().

[egmontkob]

The draft patch breaks in non-UTF-8 locales. I guess some more fundamental changes / cleanups will be needed.