Character delete patch

Removed an exploit where characters of different accounts could be deleted by a logging account session. Issue pointed out by zera.

src/client/MapleClient.java

@@ -965,8 +965,37 @@ public class MapleClient {
 		return Server.getInstance().getChannel(world, channel);
 	}
 
+        private boolean hasCharacter(int cid) throws SQLException {
+                Connection con = null;
+                PreparedStatement ps = null;
+                ResultSet rs = null;
+                
+                try {
+                        con = DatabaseConnection.getConnection();
+                        ps = con.prepareStatement("SELECT id FROM characters WHERE accountid = ?");
+                        ps.setInt(1, getAccID());
+                        
+                        rs = ps.executeQuery();
+                        while (rs.next()) {
+                                if (rs.getInt("id") == cid) {
+                                        return true;
+                                }
+                        }
+                } finally {
+                        if(rs != null && !rs.isClosed()) rs.close();
+                        if(ps != null && !ps.isClosed()) ps.close();
+                        if(con != null && !con.isClosed()) con.close();
+                }
+                
+                return false;
+        }
+        
 	public boolean deleteCharacter(int cid) {
                 try {
+                        if(!hasCharacter(cid)) {
+                                return false;
+                        }
+                    
                         return MapleCharacter.deleteCharFromDB(MapleCharacter.loadCharFromDB(cid, this, false));
                 } catch(SQLException ex) {
                         ex.printStackTrace();