commit 1009ba89b5d603ae7f1a95ef65a818c760c367cf
Author: Joris Guisson <joris.guisson@gmail.com>
Date:   Mon Oct 22 20:07:21 2012 +0200

    Backport to 4.3: Fix crash in GroupViewModel when dragging torrents over groups
    
    BUG: 308733

diff --git a/ktorrent/groups/groupviewmodel.cpp b/ktorrent/groups/groupviewmodel.cpp
index f2e99d2..b4dca7e 100644
--- ktorrent/groups/groupviewmodel.cpp
+++ ktorrent/groups/groupviewmodel.cpp
@@ -55,6 +55,9 @@ namespace kt
 	QVariant GroupViewModel::data(const QModelIndex& index, int role) const
 	{
 		Item* item = (Item*)index.internalPointer();
+        if(!item)
+            return QVariant();
+        
 		switch(role)
 		{
 			case Qt::DisplayRole:
@@ -72,6 +75,9 @@ namespace kt
 			return false;
 		
 		Item* item = (Item*)index.internalPointer();
+        if(!item)
+            return false;
+        
 		Group* group = item->group;
 		QString new_name = value.toString();
 		if(new_name.isEmpty() || gman->find(new_name))
@@ -96,13 +102,16 @@ namespace kt
 			return 1;
 		
 		Item* item = (Item*)parent.internalPointer();
-		return item->children.size();
+        if(!item)
+            return 0;
+        else
+            return item->children.size();
 	}
 
 	QModelIndex GroupViewModel::parent(const QModelIndex& child) const
 	{
 		Item* item = (Item*)child.internalPointer();
-		if(!item->parent)
+		if(!item || !item->parent)
 			return QModelIndex();
 		else
 			return createIndex(item->parent->row, 0, (void*)item->parent);
@@ -114,7 +123,7 @@ namespace kt
 			return createIndex(row, column, (void*)&root);
 		
 		Item* item = (Item*)parent.internalPointer();
-		if(row < 0 || row >= item->children.count())
+		if(!item || row < 0 || row >= item->children.count())
 			return QModelIndex();
 		
 		return createIndex(row, column, (void*)&item->children.at(row));
@@ -157,7 +166,7 @@ namespace kt
 	Qt::ItemFlags GroupViewModel::flags(const QModelIndex& index) const
 	{
 		Item* item = (Item*)index.internalPointer();
-		if(item->group && !item->group->isStandardGroup())
+		if(item && item->group && !item->group->isStandardGroup())
 			return Qt::ItemIsEnabled | Qt::ItemIsEditable | Qt::ItemIsDropEnabled;
 		else
 			return Qt::ItemIsEnabled;
@@ -218,8 +227,11 @@ namespace kt
 	
 	bool GroupViewModel::removeRows(int row, int count, const QModelIndex& parent)
 	{
+        Item* item = (Item*)parent.internalPointer();
+        if(!item)
+            return false;
+        
 		beginRemoveRows(parent, row, row + count);
-		Item* item = (Item*)parent.internalPointer();
 		for(int i = 0; i < count; i++)
 			item->children.removeAt(row);
 		int row_index = 0;
@@ -436,3 +448,4 @@ namespace kt
 
 
 }
+