FObject double free prevention of fc::empty_string

ChangeLog

@@ -1,3 +1,6 @@
+2017-10-15  Markus Gans  <guru.mail@muenster.de>
+	* FObject double free prevention of fc::empty_string
+
 2017-10-14  Markus Gans  <guru.mail@muenster.de>
 	* Fixed a bug in the FObject check of parent objects
 	* Replace the deprecated readdir_r function (CVE-2013-4237)

examples/listview.cpp

@@ -182,11 +182,11 @@ void Listview::cb_showInMessagebox (FWidget* widget, data_ptr)
 {
   FListView* listView = static_cast<FListView*>(widget);
   FListViewItem* item = listView->getCurrentItem();
-  FMessageBox info ( "Weather in " + item->getText(0)
-                   , "  Condition: " + item->getText(1) + "\n"
-                     "Temperature: " + item->getText(2) + "\n"
-                     "   Humidity: " + item->getText(3) + "\n"
-                     "   Pressure: " + item->getText(4)
+  FMessageBox info ( "Weather in " + item->getText(1)
+                   , "  Condition: " + item->getText(2) + "\n"
+                     "Temperature: " + item->getText(3) + "\n"
+                     "   Humidity: " + item->getText(4) + "\n"
+                     "   Pressure: " + item->getText(5)
                    , FMessageBox::Ok, 0, 0, this );
   info.show();
 }

examples/treeview.cpp

@@ -266,12 +266,6 @@ Treeview::Treeview (FWidget* parent)
     continent_list++;
   }
 
-  FObjectIterator iter = listView->beginOfList();
-  FObjectIterator iter_africa = iter++;
-  FListViewItem* item_africa = static_cast<FListViewItem*>(*iter_africa);
-  item_africa->expand();
-
-
   // Quit button
   Quit = new FButton (this);
   Quit->setGeometry(24, 16, 10, 1);

src/fobject.cpp

@@ -38,10 +38,12 @@ FObject::FObject (FObject* parent)
   , children_list()            // no children yet
   , has_parent(false)
 {
-  if ( parent_obj )              // add object to parent
-    parent_obj->addChild(this);
-
-  if ( parent == 0 )
+  if ( parent )                // add object to parent
+  {
+    parent->addChild(this);
+    has_parent = true;
+  }
+  else
   {
     timer_modify_lock = false;
 
@@ -71,17 +73,11 @@ FObject::FObject (FObject* parent)
       }
     }
   }
-  else
-    has_parent = true;
 }
 
 //----------------------------------------------------------------------
 FObject::~FObject()  // destructor
 {
-  if ( parent_obj )
-    parent_obj->delChild(this);
-
-  parent_obj = 0;
   delOwnTimer();  // delete all timers of this object
 
   if ( ! has_parent && timer_list )
@@ -110,6 +106,11 @@ FObject::~FObject()  // destructor
       ++iter;
     }
   }
+
+  if ( parent_obj )
+    parent_obj->delChild(this);
+
+  parent_obj = 0;
 }
 
 // public methods of FObject

src/fstring.cpp

@@ -2482,13 +2482,13 @@ inline void FString::_assign (const wchar_t* s)
 //----------------------------------------------------------------------
 inline void FString::_insert (uInt pos, uInt len, const wchar_t* s)
 {
+  if ( len == 0 )  // String s is a null or a empty string
+    return;
+
   if ( ! string )
   {
     // string is null
 
-    if ( len == 0 )  // String s is also a null string
-      return;
-
     length = len;
     bufsize = FWDBUFFER + length + 1;