#2202 Setting -sashwidth to 0 makes wish abort on X11

[Anonymous]

In X11, setting the -sashwidth option of panedwindow to 0 makes
wish abort with a bad X request when Tk try to create a proxy window.
Apparently in X is invalid to create a window of width 0.

emiliano@erizo:~$ wish8.4
% pack [panedwindow .pw -sashwidth 0]
% .pw add [label .l1 -text Hello]
% .pw add [label .l2 -text world]
%

and after resizing the pane I get:

X Error of failed request: BadValue (integer parameter out of range for operation)
Major opcode of failed request: 1 (X_CreateWindow)
Value in failed request: 0x0
Serial number of failed request: 232
Current serial number in output stream: 234
emiliano@erizo:~$

The same problem occurs if the proxy window is created by the script:

emiliano@erizo:~$ wish8.4
% pack [panedwindow .pw -sashwidth 0]
% .pw add [label .l1 -text Hello]
% .pw add [label .l2 -text world]
% .pw proxy place 0 0
X Error of failed request: BadValue (integer parameter out of range for operation)
Major opcode of failed request: 1 (X_CreateWindow)
Value in failed request: 0x0
Serial number of failed request: 152
Current serial number in output stream: 154
emiliano@erizo:~$

[Emiliano]

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user_id=1852298
Originator: NO

I'm the original poster. The bug is still present in 8.5.2
After some source dive I come up with this patch that restrict
the size of the proxy window to 1 pixel and above.
This effectively workarounds the problem.

--- generic/tkPanedWindow.c.orig 2008-05-13 19:52:10.000000000 -0300
+++ generic/tkPanedWindow.c 2008-05-13 20:04:08.000000000 -0300
@@ -2818,7 +2818,17 @@
x = 0;
}
y = Tk_InternalBorderWidth(pwPtr->tkwin);
- sashWidth = pwPtr->sashWidth;
+
+ /* If the sashwidth is less than 1, use 1 as the width of the
+ proxy window. This workarounds bug #1639824
+ */
+
+ if (pwPtr->sashWidth > 0) {
+ sashWidth = pwPtr->sashWidth;
+ } else {
+ sashWidth = 1;
+ }
+
sashHeight = Tk_Height(pwPtr->tkwin) -
(2 * Tk_InternalBorderWidth(pwPtr->tkwin));
} else {
@@ -2826,7 +2836,13 @@
y = 0;
}
x = Tk_InternalBorderWidth(pwPtr->tkwin);
- sashHeight = pwPtr->sashWidth;
+
+ if (pwPtr->sashWidth > 0) {
+ sashHeight = pwPtr->sashWidth;
+ } else {
+ sashHeight = 1;
+ }
+
sashWidth = Tk_Width(pwPtr->tkwin) -
(2 * Tk_InternalBorderWidth(pwPtr->tkwin));
}

[Donal K. Fellows]

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user_id=79902
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A fix is applied to the HEAD; needs someone to backport to earlier branches: 8.5, 8.4 only if there's going to be another release in that series. Handing off to release manager for decisions on that front.

[Don Porter]

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user_id=80530
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must backport before 8.5.3 or 8.4.20

[Don Porter]

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user_id=80530
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Backported for 8.5.3.

Existing patch is ineffective
as a fix for the bugs in Tk 8.4.19,
so that's left untouched unless/until
a patch that works on that branch
is contributed.