Re: [lmi] Untimely "save" dialog [Was: wxmsw-2.9.0 regression: crash when a messagebox should appear]

[Greg Chicares]

On 2009-03-09 20:23Z, Vadim Zeitlin wrote:
[...]
> Notice that an alternative could be to move Run() inside try/catch clause
> instead but it seems inconsistent to catch only some exceptions and not all
> of them, even if now (i.e. with my latest changes to wx) catching them or
> letting them escape shouldn't change the observable behaviour.

I'm not sure whether this is worth examining, but I'll just report it
and let you decide. I experimentally made a flawed change, and got a
crash. I'm still using snapshot 'wxWidgets-2009-03-12.tar.bz2', BTW.

Index: illustration_view.cpp
===================================================================
RCS file: /sources/lmi/lmi/illustration_view.cpp,v
retrieving revision 1.102
diff -U 3 -r1.102 illustration_view.cpp
--- illustration_view.cpp       6 Jan 2009 15:01:22 -0000       1.102
+++ illustration_view.cpp       13 Mar 2009 19:23:30 -0000
@@ -189,25 +189,34 @@
         return ViewEx::OnCreate(doc, flags);
         }

+retry:
     try
         {
         if(wxID_OK != EditProperties())
             {
             return false;
             }
+        if(!ViewEx::OnCreate(doc, flags))
+            {
+            return false;
+            }
+
+        Run();
         }
     catch(...)
         {
         report_exception();
-        return false;
+        goto retry;
+//        return false;
         }
-
+#if 0
     if(!ViewEx::OnCreate(doc, flags))
         {
         return false;
         }

     Run();
+#endif // 0
     return true;
 }

I say this is flawed because it calls OnCreate() repeatedly for the
same document. I believe I should instead refactor Run() into two
private functions, to be used here thus:
  EditProperties();
  ThePartOfRunThatDetectsInvalidInput(); // validate and calculate
  OnCreate(...);
  TheOtherPartOfRun(); // show calculation results in wxHtml

But in case you're striving to prevent a crash even in the abusive
case presented by the above patch, here's how to reproduce it:
  File | New | Illustration
  in "Extra policy fee" field, enter "0,1000" without quotes [invalid]
  OK
  OK to "Input validation problems" messagebox
[dialog appears anew]
  in "Extra policy fee" field, enter "0" without quotes [that's valid]
  OK
Now you see two views. Close either one. Say "No" when prompted to save
changes. Then it crashes.

I'll send full "Dr. MinGW" crash reports privately to save bandwidth.