If wchar is not included in ncurses, mc 4.8.26 fails to compile.

[mc-butler]

Important

This issue was migrated from Trac:

Origin	https://midnight-commander.org/ticket/4200
Reporter	mrbump (rudi@….com)

With the introduction of shadows in mc (which are nice) on platforms that support them with the following commit - https://github.com/MidnightCommander/mc/commit/8b4386df83ab5a525f0568113fe1e53d362f433e.patch and Ticket #4120: draw shadows for dialog boxes and menus.

Mc 4.8.26 fails to compile on LibreELEC. - https://libreelec.tv/ - the Tagline being Just enough OS for KODI

We use --disable-widec in the ncurses build, https://github.com/LibreELEC/LibreELEC.tv/blob/master/packages/devel/ncurses/package.mk

Reverting the whole patch fixes the compile, but it would be ideal to use alternatives or limit shadows if wchar is not available.

Results of the failed compile

./.libs/libinternal.a(tty-ncurses.o):tty-ncurses.c:function tty_colorize_area: error: undefined reference to 'mvin_wchnstr'
./.libs/libinternal.a(tty-ncurses.o):tty-ncurses.c:function tty_colorize_area: error: undefined reference to 'getcchar'
./.libs/libinternal.a(tty-ncurses.o):tty-ncurses.c:function tty_colorize_area: error: undefined reference to 'setcchar'
./.libs/libinternal.a(tty-ncurses.o):tty-ncurses.c:function tty_colorize_area: error: undefined reference to 'mvadd_wchnstr'

Note

Original attachments:

• 4200_ncurses_disable_widec.patch (raw) by andrew_b (@aborodin) on Feb 15, 2021 at 17:40 UTC

[mc-butler]

Changed by mrbump (rudi@….com) on Feb 13, 2021 at 11:43 UTC (comment 1)

The code that has the wchar is

+++ b/lib/tty/tty-ncurses.c
@@ -533,6 +550,38

/* --------------------------------------------------------------------------------------------- */

+void
+tty_colorize_area (int y, int x, int rows, int cols, int color)
+{
+    cchar_t *ctext;
+    wchar_t wch[10];   /* TODO not sure if the length is correct */
+    attr_t attrs;
+    short color_pair;
+
+    if (!use_colors || !tty_clip (&y, &x, &rows, &cols))
+        return;
+
+    tty_setcolor (color);
+    ctext = g_malloc (sizeof (cchar_t) * (cols + 1));
+
+    for (int row = 0; row < rows; row++)
+    {
+        mvin_wchnstr (y + row, x, ctext, cols);
+
+        for (int col = 0; col < cols; col++)
+        {
+            getcchar (&ctext[col], wch, &attrs, &color_pair, NULL);
+            setcchar (&ctext[col], wch, attrs, color, NULL);
+        }
+
+        mvadd_wchnstr (y + row, x, ctext, cols);

[mc-butler]

Changed by mrbump (rudi@….com) on Feb 13, 2021 at 11:56 UTC (comment 2)

Original change that created the issue #4102

[mc-butler]

Changed by andrew_b (@aborodin) on Feb 13, 2021 at 13:02 UTC (comment 3)

• Component changed from mc-core to mc-tty
• Resolution set to invalid
• Status changed from new to closed
• Milestone Future Releases deleted

Fixed as #4181.

[mc-butler]

Changed by mrbump (rudi@….com) on Feb 14, 2021 at 0:50 UTC (comment 4)

Whilst that patch fixed MacOS it doesn’t fix LibreELEC as wide char is not included. I had tested that patch as I had compiled against master https://github.com/MidnightCommander/mc/commits/master . If you could suggest a direction of what would be acceptable to the mc team, I would be happy to develop a code fix. As in tty-slang I see that tty_colorize_area is essentially a noop.

Should I write a —without-wchar configure option?

[mc-butler]

Changed by zaytsev (@zyv) on Feb 14, 2021 at 10:12 UTC (comment 5)

How is it possible that LibreELEC doesn't have a definition of wchar_t? Kodi itself seems to use it all over the place... How do you solve this problem?

To me it seems that of course you do have wchar_t, only for some reason we cannot understand yet you compile ncurses with --disable-widec, so even though mc does compile against ncurses, according to your log the linking fails, because mvadd_wchnstr function cannot be found. Just compile ncurses --enable-widec to solve this problem if you can. I would be surprised if mc interface will be rendered correctly if you compile against ncurses with --disable-widec anyways.

[mc-butler]

Changed by andrew_b (@aborodin) on Feb 15, 2021 at 17:40 UTC

• Attachment 4200_ncurses_disable_widec.patch (raw) added

[mc-butler]

Changed by andrew_b (@aborodin) on Feb 15, 2021 at 17:40 UTC (comment 6)

Please test the attached patch.

[mc-butler]

Changed by andrew_b (@aborodin) on Feb 28, 2021 at 14:02 UTC (comment 7)

ping

[mc-butler]

Changed by andrew_b (@aborodin) on Mar 7, 2021 at 15:56 UTC (comment 8)

@mrbump, please let me know if this patch works or not.

[mc-butler]

Changed by mrbump (rudi@….com) on Aug 23, 2021 at 13:49 UTC (comment 9)

Hi @andrew_b

we just pulled the patch into 4.8.27. And removed the previous revert patch. All works as expected. LibreELEC/LibreELEC.tv#5562

Regards
Rudi

[mc-butler]

Changed by andrew_b (@aborodin) on Aug 28, 2021 at 8:47 UTC (comment 10)

• Status changed from closed to reopened
• Milestone set to 4.8.28
• Branch state changed from no branch to on review
• Resolution invalid deleted

Branch: 4200_ncurses_disable_widec
[e7bbf72]

[mc-butler]

Changed by andrew_b (@aborodin) on Aug 28, 2021 at 8:49 UTC (comment 11)

• Votes set to mrbump andrew_b
• Branch state changed from on review to approved

[mc-butler]

Changed by andrew_b (@aborodin) on Aug 28, 2021 at 8:50 UTC (comment 12)

• Resolution set to fixed
• Votes changed from mrbump andrew_b to committed-master
• Branch state changed from approved to merged
• Status changed from reopened to closed

Merged to master: [375f2a7].