Tk Source Code

Setup: one X display with more than one screen. Can be emulated with the following command:

Xvfb :1 -screen 0 800x600x24+32 -screen 1 800x600x24+32 &

Running the script below in wish:

env DISPLAY=:1 ../rel/bin/wish

foreach s {0 1} {
    set screen :1.$s;
    set t [::toplevel .t$s -screen $screen]
    set mm [::ttk::label $t.mm];
    pack $mm;
}

causes wish to abort:

Tk_GetFontFromObj called with non-existent font!
Abort (core dumped)

1 warning during Tk compilation:
     Tk/generic/ttk/ttkCache.c: In function 'InitCacheWindow':
     Tk/generic/ttk/ttkCache.c:256:64: warning: unused parameter 'tkwin' [-Wunused-parameter]
     static void InitCacheWindow(Ttk_ResourceCache cache, Tk_Window tkwin)

Looking at this, instead of a separate 'tkwin' parameter, the one in the cache ('cache->tkwin') is used. The logical question is then: shouldn't this be done in more places? For example like: [ed67b8e0980fd5af|this]?

Credit corrected (Thanks, @chrstphrchvz) and merged to all branches

Jan, thanks for merging. Could the changes file please credit werner ? I am only a patch tester/committer in this case. Thanks

[401a5f8f7e48200c|merged] to 8.6 now.

Please consider branch bug-a80e5ff9 for merging. In hopes of getting this issue finally fixed, I have separated out Christian Werner's fix for this issue from the bug-c23f79ef96 branch.

I concur.

I have run into this same issue and diagnosed the same cause when I was working on [c95d4691ff].

See also this discussion on Tcl Core list, that I started when working on the above mentioned ticket.

All this got eventually stalled (help welcome!).

Same observation with different displays:

Xvfb :1 &
Xvfb :2 &

% toplevel .t1 -screen :1;
.t1
% toplevel .t2 -screen :2;
.t2
% ttk::label .t1.l -text sometext;
.t1.l
% ttk::label .t2.l -text sometext;
Tk_GetFontFromObj called with non-existent font!