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- Newsgroups: comp.windows.x.intrinsics
- Path: sparky!uunet!cs.utexas.edu!uwm.edu!spool.mu.edu!yale.edu!yale!mintaka.lcs.mit.edu!expo.lcs.mit.edu!converse
- From: converse@expo.lcs.mit.edu (Donna Converse)
- Subject: Re: core dump with Form widget
- Message-ID: <1992Dec30.220710.1383@mintaka.lcs.mit.edu>
- Keywords: Form widget, XtDestroyWidget
- Sender: converse@excess.lcs.mit.edu (Donna Converse)
- Organization: X Consortium, MIT Laboratory for Computer Science
- References: <1992Dec23.091102.16657@news.th-darmstadt.de>
- Date: Wed, 30 Dec 1992 22:07:10 GMT
- Lines: 51
-
-
- > Our system is: SunOS 4.1.1, X11R4 on sun4c
- >
- > We have got a menu with callbacks poping up Popup-Shells. These Shells contain
- > a Form-widget, which in turn contains some labels, buttons, a scrollbar and a
- > list widget.
- > After leaving the popup, we use XtDestroyWidget on the popup-shell widget.
- > Next time a menu item is selected, all widgets (including the popup shell)
- > are created once again.
- > So far, so good ! It works well for the first time, perhaps for the second, too
- > but then we receive a "Segmentation fault (core dumped)" or a Bus error.
-
-
- Fixed in R5.
-
- ------- Forwarded Message
-
- Date: 12 Apr 91 13:13:34 GMT
- From: rod@scooter.rosemount.com (Rodney Drenth)
- Organization: Rosemount Industrial
- Subject: Error: XmuCvtStringToWidget
- To: xpert@expo.lcs.mit.edu
-
- An error exists in the way the String to Widget Conversion routine is
- registered with the resource converter in the Athena Form WIdget.
- The resource converter should not cache conversions, but does. Under
- certain circumstances it will cause sporatic bus errors and segmentation
- faults.
-
- The problem affects the fromVert and fromHoriz resources in the Athena
- Form widget. If these are specified in a resource file (not in a program)
- and if the form widget and its children can be destroyed and re-created, it is
- possible for the widget ID of the form widget to stay the same but the
- Widget ID's of the children to be different. When this occurs, and
- because the Name To Widget conversion is cached, the resource conversion
- returns incorrect values, which cause segmentation faults and core dumps.
-
- The problem can be corrected by either not specifying the fromHoriz and
- fromVert resources in resource files, or by making a copy of the
- XmuCvtStringToWidget function, modifying it so that it is a new type
- resource converter, and changing the ClassInitialize function in the
- Athena Form Widget to install your revised StringToWidget function with
- XtCacheNone specified.
-
- Rodney Drenth
-
- ------- End of Forwarded Message
-
-
- Donna Converse
- MIT X Consortium
-