Bug#241469: here's a patch to implement it

[Zefram <zefram@fysh.org>]

Oops, missed out the documentation:

diff -ru3 ./xc/programs/twm/twm.man ../build-tree.new/xc/programs/twm/twm.man
--- ./xc/programs/twm/twm.man	2002-10-12 17:06:46.000000000 +0100
+++ ../build-tree.new/xc/programs/twm/twm.man	2004-10-23 11:52:36.000000000 +0100
@@ -600,7 +600,7 @@
 file contains a completely new set of bindings and definitions.
 .IP "\fBNoGrabServer\fP" 8
 This variable indicates that \fItwm\fP should not grab the server
-when popping up menus and moving opaque windows.
+when popping up menus and moving and resizing opaque windows.
 .IP "\fBNoHighlight\fP [{ \fIwin-list\fP }]" 8
 This variable indicates that borders should not be highlighted to track the
 location of the pointer.  If the optional \fIwin-list\fP is given, highlighting
@@ -665,6 +665,11 @@
 the window instead of just an outline so that the user can immediately see
 what the window will look like in the new position.  This option is typically
 used on fast displays (particularly if \fBNoGrabServer\fP is set).
+.IP "\fBOpaqueResize\fP" 8
+This variable indicates that the \fBf.resize\fP function should actually resize
+the window instead of just an outline so that the user can immediately see
+what the window will look like with the new size.  This option is typically
+used on fast displays (particularly if \fBNoGrabServer\fP is set).
 .IP "\fBPixmaps\fP { \fIpixmaps\fP }" 8
 This variable specifies a list of pixmaps that define the appearance of various
 images.  Each entry is a keyword indicating the pixmap to set, followed by a 
@@ -1094,8 +1099,10 @@
 .IP "\fBf.refresh\fP" 8
 This function causes all windows to be refreshed.
 .IP "\fBf.resize\fP" 8
-This function displays an outline of the selected window.  Crossing a border
-(or setting \fBAutoRelativeResize\fP) will cause the outline to begin to 
+This function resizes an outline of the selected window (or the window itself
+if the \fBOpaqueResize\fP variable is set).  Crossing a border
+(or setting \fBAutoRelativeResize\fP) will cause the outline
+(or window) to begin to 
 rubber band until the invoking button is released.  To abort a resize,
 press another button before releasing the first button.
 .IP "\fBf.restart\fP" 8
END_OF_PATCH