TCanvas serialization;Transmission over a TSocket connection

Hello rooters!

I developed an application a year ago which renderes some simple
canvases with graphs on them and sends them over a
TSocket-Connection to another computer where they are shown.
I am using RedHat 9 machines.
Everything worked well with root 3.05.07.

Right now I have to redo some of this code and started upgrading
to the new 4.01.02. I encountered some problems with my
TCanvas and graphs. So I reduced the problem to build a TCanvas
on the “server” side and view it on the “client” side.

I recently get a black window on the server, whole screen in size,
and a warning message:
Warning in TCanvas::ResizePad: c_signal_fft_one_canvas_0 height changed from 32000 to 10

Beforhand (3.05.07) the window was half screen in size and with
valid content.

I then tried to diff TCanvas->Dump on the server (before transmission)
and on the client (after transmission).

I attached the main differences of these dumps (I stripped all the ptr values as long as there were valid references), see below.
I wonder why the windowSize attributes are zero on the client side.

I tried a google search finding just one mailing list conversation
covering this errormessage, with no exact hint on the problem.
Hopefully, one of you out there has a hint for me.

Thanks in advance,
from near Munich, Germany,
Michael Wirz

Diff of the two ->Dump()-outputs of the TCanvas objects

1,2c1,2
< c_signal: -----------------------------
< ==>Dumping object at:8bc66d8, name=c_signal_fft_one_canvas_0, class=TCanvas

c: ---------------------------------
==>Dumping object at:8e87dc0, name=c_signal_fft_one_canvas_0, class=TCanvas

21,22c21,22
< fWindowWidth 600 Width of window (including borders, etc.)
< fWindowHeight 800 Height of window (including menubar, borders, etc.)

fWindowWidth 0 Width of window (including borders, etc.)
fWindowHeight 0 Height of window (including menubar, borders, etc.)
25,28c25,28
< fEvent -1 !Type of current or last handled event
< fEventX -1 !Last X mouse position in canvas
< fEventY -1 !Last Y mouse position in canvas
< fCanvasID 0 !Canvas identifier


fEvent 0 !Type of current or last handled event
fEventX 0 !Last X mouse position in canvas
fEventY 0 !Last Y mouse position in canvas
fCanvasID -1 !Canvas identifier

36c36
< *fCanvasImp ->8bc9cf8 !Window system specific canvas implementation

*fCanvasImp ->0 !Window system specific canvas implementation

85c85
< fPixmapID 0 ! Off-screen pixmap identifier

fPixmapID -1 ! Off-screen pixmap identifier

111c111
< *fFrame ->95b13e0 ! Pointer to 2-D frame (if one exists)

*fFrame ->0 ! Pointer to 2-D frame (if one exists)
114c114
< *fPadView3D ->360 ! 3D View of this TPad


*fPadView3D ->0 ! 3D View of this TPad

Could you repeat this exercise with the CVS head version?

Rene