Re: segfault

On Thu, 10 Sep 2009 14:51:46 +0200 Vadim Zeitlin <[email protected]> wrote:

VZ> NB> with latest svn when trying to view html message:
VZ> NB> 
VZ> NB> Program received signal SIGSEGV, Segmentation fault.
VZ> NB> 0x323d6465 in ?? ()
VZ> ...
VZ> NB> (gdb) bt
VZ> NB> #0  0x323d6465 in ?? ()
VZ> NB> #1  0xb7fa3c47 in wxHtmlWindow::CreateLayout (this=0x8aaf000)
VZ> NB>     at ../wxWidgets/src/html/htmlwin.cpp:693
VZ> 
VZ>  This is really strange, m_Cell may not be NULL here (it's checked for just
VZ> above) so apparently it's a dangling pointer but I don't know how could
VZ> this happen and there have definitely been no recent changes to wxHTML
VZ> which could explain it.

I found the bad change by bitsecting:

Index: src/html/htmlwin.cpp
===================================================================
--- htmlwin.cpp	(revision 61771)
+++ htmlwin.cpp	(revision 61772)
@@ -467,11 +467,8 @@
     SetBackgroundImage(wxNullBitmap);
 
     m_Parser->SetDC(dc);
-    if (m_Cell)
-    {
-        delete m_Cell;
-        m_Cell = NULL;
-    }
+
+    delete m_Cell;
     m_Cell = (wxHtmlContainerCell*) m_Parser->Parse(newsrc);
     delete dc;
     m_Cell->SetIndent(m_Borders, wxHTML_INDENT_ALL, wxHTML_UNITS_PIXELS);

61771 works, 61772 crashes.

Regards,
Nerijus

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