handle FNERR_INVALIDFILENAME which happens if an invalid file name is passed to wxFileDialog (#9688) [backport from trunk]

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@55207 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -133,12 +133,13 @@ wxMSW:
   wxWidgets 2.8.9 or later.
 - Fix keyboard support in wxSpinCtrl broken in 2.8.8.
 - Compile fix for WinCE in window.cpp (no VkKeyScan in Windows CE).
-- Fix quoting of arguments passed to wxExecute(char **) (Brian Ravnsgaard Riis).
 - Support disabling items before adding them to the menu (Christian Walther).
 - Allow to call SetFont(wxNullFont) to reset the font to default.
 - Implement UUID::operator==() and !=() (SQLAware Corporation).
 - Fixed long standing (introduced in 2.6.3) bug which resulted in always
   creating a DIB and not DDB in wxBitmap(const wxImage&) ctor.
+- Fix the bug with wxFileDialog not being shown at all if the default file name
+  was invalid.
 
 wxGTK:
 

src/msw/filedlg.cpp

@@ -438,6 +438,13 @@ int wxFileDialog::ShowModal()
     DWORD errCode;
     bool success = DoShowCommFileDialog(&of, m_windowStyle, &errCode);
 
+    if ( !success && errCode == FNERR_INVALIDFILENAME && of.lpstrFile[0] )
+    {
+        // this can happen if the default file name is invalid, try without it now
+        of.lpstrFile[0] = _T('\0');
+        success = DoShowCommFileDialog(&of, m_windowStyle, &errCode);
+    }
+
 #ifdef wxTRY_SMALLER_OPENFILENAME
     // the system might be too old to support the new version file dialog
     // boxes, try with the old size