Tk Source Code

Most widgets return configure information with synonyms
pointing to the associated configure option switch. The
canvas, scrollbar and text widgets return synonyms
pointing to the database name. e.g.

% button .b
.b
% join [lsort [.b configure]] \n
...
-background background Background #d9d9d9 #d9d9d9
-bd -borderwidth
-bg -background
-bitmap bitmap Bitmap {} {}
-borderwidth borderWidth BorderWidth 2 2
...
-fg -foreground
-foreground foreground Foreground Black Black
...

(Note how -bg maps to -background and -bd to -borderwidth)

% text .t
.t
% join [lsort [.t configure]] \n
...
-background background Background #d9d9d9 #d9d9d9
-bd borderWidth
-bg background
-borderwidth borderWidth BorderWidth 2 2
...
-fg foreground
-foreground foreground Foreground Black Black
...

(Here -bg maps to background and -bd to borderWidth}

In 8.3.5, the frame, message and toplevel widgets also
suffered from this bug, but appear fixed in 8.4.

The text widget has reported the option name since it was converted to the new option system in Tk 8.5 ([e58248ce5f], TIP 155), but canvas and scrollbar still use Tk_ConfigureInfo(), which reports a synonym with the database name of the option it refers to ("borderWidth") instead of the option name ("-borderwidth").

Fixed in [03d1a43c33] (branch oldconfig-synonym-info): Tk_ConfigureInfo() now reports the name of the option, like Tk_GetOptionInfo(). As noted by aspect, the documentation of TK_CONFIG_SYNONYM was wrong about the dbName field: it holds the database name of the option (which is what all option tables and the lookup use), not its name; corrected. Tests canvas-1.45.1 and scrollbar-1.100.

This was reported again in comp.lang.tcl.

More in tkOldConfig.c!  Since I was in here recently, here are some notes:


This appears to stem from a documentation:implementation mismatch in tkOldConfig.c that has existed since at least 1999:

http://core.tcl.tk/tk/artifact/e71fd7412b3dc34d?ln=339-341

.. suggests that TK_CONFIG_SYNONYM should be followed by an argvName in the dbName field, but ..

http://core.tcl.tk/tk/artifact/4c31292bd7cc7fea?ln=295-305

.. disagrees.  Formatting appears to be controlled here:

http://core.tcl.tk/tk/artifact/4c31292bd7cc7fea?ln=704-706


If this analysis is correct, I suspect the best approach is to correct the documentation and the formatting code;  FindConfigSpec can be left alone.