fix generation of events for an initially empty wxDirPickerCtrl

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@54732 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -132,6 +132,7 @@ wxMSW:
 wxGTK:
 
 - Fix masking of disabled bitmaps in wxMenuItem and wxStaticBitmap.
+- Fix generation of events for an initially empty wxDirPickerCtrl.
 
 wxMac:
 
@@ -426,7 +427,7 @@ All:
   overlaps UTF-8 characters boundary.
 - Account for lines without newline at the end in wxExecute().
 - Added wxString::char_str(), wchar_str(), From8BitData(), To8BitData(),
-  FromUTF8(), ToUTF8() and utf8_str() methods for forward compatiblity
+  FromUTF8(), ToUTF8() and utf8_str() methods for forward compatibility
   with wxWidgets 3.
 
 All (Unix):

src/gtk/filepicker.cpp

@@ -263,8 +263,14 @@ wxDirButton::~wxDirButton()
     	m_dialog->m_widget = NULL;
 }
 
-void wxDirButton::SetPath(const wxString &str)
+void wxDirButton::SetPath(const wxString& str)
 {
+    if ( m_path == str )
+    {
+        // don't do anything and especially don't set m_bIgnoreNextChange
+        return;
+    }
+
     m_path = str;
 
     // wxDirButton uses the "current-folder-changed" signal which is triggered also