FLTK on NetBSD very slow on X11 with Unicode locale

[ManoloFLTK]

This is the transposition of STR#2961 to a github issue.
The overall message from that STR is that the call to XOpenIM() performed each time a window gets closed renders FLTK very slow under NetBSD with Unicode locale. The effect is particularly noticeable when using a menubar where each time the mouse changes toplevel menu a window is closed.

To Reproduce
Run test/editor under NetBSD with Unicode locale.
Open a menu and move the mouse left or right to change menu.

Expected behavior
Menu changes should be swift but they are very slow.

FLTK Version

• Version: 1.3.x or 1.4 : same cause, same effect

Operating System / Platform:

• OS: NetBSD
• With Debian, no slowdown but the frequent calls to XOpenIM() do occur

Linux/Unix Runtime, if applicable:

• X11

[ManoloFLTK]

@michaelbaeuerle To Michael Bäuerle: please apply the attached patch to the current version of FLTK 1.4 and report here whether the slowdown disappears under NetBSD and a Unicode locale. I would really expect it does.
If so, I will commit that change. I could also apply it to branch 1.3 if you need to keep using 1.3.

issue935.patch

[michaelbaeuerle]

Yes, with this patch there is no delay anymore.
Thank you for looking at this problem!

[Albrecht-S]

👍 @ManoloFLTK Awesome, thank you very much for fixing this long-standing issue!

Manolo wrote:

I could also apply it to branch 1.3 if you need to keep using 1.3.

@michaelbaeuerle What about your further usage of 1.3?

@ManoloFLTK Would you like to add this to 1.3 as well? I'm planning to release 1.3.10 soon (either before 1.4.0 or shortly after 1.4.0).

[ManoloFLTK]

@Albrecht-S I've also committed to branch 1.3 (807d205) the fix for this issue.

[Albrecht-S]

@ManoloFLTK Thanks.