Attachment 186611 Details for Bug 277381 – Explanation of process to duplicate as well as possible fix code.

Explanation of process to duplicate as well as possible fix code.

OpenMotif 2.3 tooltip Error.txt (text/plain), 3.92 KB, created by Steve Hild on 2007-09-04 20:53:33 UTC

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Creator: Steve Hild

Created: 2007-09-04 20:53:33 UTC

Size: 3.92 KB

patch

obsolete

>Our application has a menu that has a selection which creates a new window with a close decoration.
>User can move mouse over window.
>User closes window using close button.
>
>
>Basic steps on how our application Creates window:
>---------------------------------------------------------------------------------------------------
>1. mytop = XtAppCreateShell NULL, Name, topLevelShellWidgetClass, DISPLAY, args, n);
>      where args set that the shells args are
>         XmNmwmInputMode = MWM_INPUT_MODELESS
>         XmNmwmFunctions = MWM_FUNC_MOVE, MWM_FUNC_RESIZE | MWM_FUNC_MAXIMIZE, MWM_FUNC_CLOSE
>         XmNmwmDecorations = MWM_DECOR_BORDER, MWM_DECOR_TITLE, MWM_DECOR_MENU, 
>           (This calls InitializePrehook which checks to see if the XmQTtoolTipConfig trait is available for the widget and if not it is allocated             and set into the TraitSet. Label is NULL.)
>
>2. xw = XmCreateMainWindow(mytop, title, args, n);
>3. client = XmCreateDrawingArea(xw, "client", args, n);
>4. gadget = XmCreateLabelGadget(client, "", args, n);
>5. XtManageChild(gadget);
>6. XtManageChild(client);
>7. XtManageChild(xw);
>8. XtRealizeWidget(mytop);
>
>Move mouse over window.
>--------------------------------------------------------------------------
>ToolTipGetData is called which finds the top parent which happens to be mytop.
>It then gets the XmQTtoolTipConfig trait for mytop, since mytops ToolTipConfig trait doesnt have a label yet it creates a Shell widget associated to mytop and then a label associated to the shell and the label pointer is saved in the trait.
>
>Destroying window:
>----------------------------------------------------------------------------------
>1. XtUnmapWidget(mytop); 
>2. XtDestroyWidget(mytop);
>Everything gets freed and destroyed associated to mytop, including the tooltip label and its shell that was saved in the tooltip trait. The label attribute of the ToolTipConfig trait is not NULLed or removed.
>
>Open a subsequent window that causes SEGV
>-------------------------------------------------------------------------------
>The new top Widget handle from the XtAppCreateShell call happens to be the same as mytop from above.
>Move cursor over window.
>ToolTipGetData gets called.
>	First it looks for tooltip Trait for the top widget. Finds one and then pass trait back to calling routine which attempts to access the label value which isnt valid and causes a SEGV error.
>
>
>Updated lib/Xm/Primitive.c
>------------------------------------------------------------------------
>
>Added the following includes to get ToolTip info.
>------------------------------------------------------------------------
>#include <Xm/ToolTipCT.h>
>
>#include "ToolTipI.h"
>#include "TraitI.h"
>
>
>This is updated Destroy function
>-----------------------------------------------------------------------
>/************************************************************************
> *
> *  Destroy
> *      Clean up allocated resources when the widget is destroyed.
> *
> ************************************************************************/
>static void
>Destroy(
>        Widget w )
>{
>   XmPrimitiveWidget pw = (XmPrimitiveWidget) w ;
>   Widget tiplabel;
>
>   _XmNavigDestroy(w);
>
>   _XmToolTipLeave(w, NULL, NULL, NULL);
>
>   /* Get the tool tip label associated to this widget. */
>   tiplabel = XmToolTipGetLabel(w);
>
>   /* If this is the tool tip label then we need to clean up the 
>   ** label setting for the XmToolTipConfig Trait associated to this widget. */
>   if (tiplabel == w)
>      {
>      Widget top = w;
>      XmToolTipConfigTrait ttp;
>
>      while (XtParent (top))
>      {
>         top = XtParent (top);
>      }
>
>      ttp = (XmToolTipConfigTrait) XmeTraitGet (top, XmQTtoolTipConfig);
>
>      if (ttp->label != NULL)
>         ttp->label = NULL;
>
>      }
>   XtReleaseGC( w, pw->primitive.top_shadow_GC);
>   XtReleaseGC( w, pw->primitive.bottom_shadow_GC);
>   XtReleaseGC( w, pw->primitive.highlight_GC);
>
>}
>
>
>

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