perform some checks before adding a new operation to the list. made

* include/GParted_Core.h,
  src/GParted_Core.cc,
  src/Win_GParted.cc: perform some checks before adding a new
  operation to the list.
* src/Partition.cc: made get_length() a bit safer

ChangeLog

@@ -1,3 +1,11 @@
+2006-07-20 Bart Hakvoort <hakvoort@cvs.gnome.org>
+
+	* include/GParted_Core.h,
+	  src/GParted_Core.cc,
+	  src/Win_GParted.cc: perform some checks before adding a new
+	  operation to the list.
+	* src/Partition.cc: made get_length() a bit safer
+
 2006-07-19 Bart Hakvoort <hakvoort@cvs.gnome.org>
 
 	* src/Dialog_Progress.cc: added FIXME

include/GParted_Core.h

@@ -38,7 +38,7 @@ public:
 	void set_user_devices( const std::vector<Glib::ustring> & user_devices ) ;
 	void set_devices( std::vector<Device> & devices ) ;
 	
-	bool snap_to_cylinder( const Device & device, Partition & partition ) ;
+	bool snap_to_cylinder( const Device & device, Partition & partition, Glib::ustring & error ) ;
 	bool apply_operation_to_disk( Operation * operation );
 	
 	bool set_disklabel( const Glib::ustring & device_path, const Glib::ustring & disklabel ) ;

src/GParted_Core.cc

@@ -229,7 +229,7 @@ void GParted_Core::set_devices( std::vector<Device> & devices )
 	fstab_info .clear() ;
 }
 
-bool GParted_Core::snap_to_cylinder( const Device & device, Partition & partition ) 
+bool GParted_Core::snap_to_cylinder( const Device & device, Partition & partition, Glib::ustring & error ) 
 {
 	if ( ! partition .strict )
 	{
@@ -256,11 +256,26 @@ bool GParted_Core::snap_to_cylinder( const Device & device, Partition & partitio
 		if ( partition .sector_end > device .length )
 			partition .sector_end = device .length -1 ;
 
+		//ok, do some basic checks on the partition..
+		if ( partition .get_length() <= 0 )
+		{
+			error = String::ucompose( _("A partition cannot have a length of %1 sectors"),
+						  partition .get_length() ) ;
+			return false ;
+		}
+
+		if ( partition .get_length() < partition .sectors_used )
+		{
+			error = String::ucompose( 
+				_("A partition with used sectors (%1) greater than it's length (%2) is not valid"),
+				partition .sectors_used,
+				partition .get_length() ) ;
+			return false ;
+		}
+
 		//FIXME: it would be perfect if we could check for overlapping with adjacent partitions as well,
 		//however, finding the adjacent partitions is not as easy as it seems and at this moment all the dialogs
 		//already perform these checks. A perfect 'fixme-later' ;)
-		
-		//FIXME: what kind of errorchecking could we do here? maybe checking if partitionlenght > used?
 	}
 
 	return true ;

src/Partition.cc

@@ -148,7 +148,10 @@ void Partition::add_paths( const std::vector<Glib::ustring> & paths, bool clear_
 
 Sector Partition::get_length() const 
 {
+	if ( sector_start >= 0 && sector_end >= 0 )
 		return sector_end - sector_start + 1 ;
+	else
+		return -1 ;
 }
 
 Glib::ustring Partition::get_path() const

src/Win_GParted.cc

@@ -616,8 +616,11 @@ void Win_GParted::Add_Operation( OperationType operationtype,
 			break;
 	}
 
-	//FIXME: do this in two separate steps and be more verbose in case of error..
-	if ( operation && gparted_core .snap_to_cylinder( operation ->device, operation ->partition_new ) )
+	if ( operation )
+	{ 
+		Glib::ustring error ;
+		if ( operation ->type == GParted::DELETE ||
+		     gparted_core .snap_to_cylinder( operation ->device, operation ->partition_new, error ) )
 		{
 			operation ->create_description() ;
 
@@ -628,7 +631,6 @@ void Win_GParted::Add_Operation( OperationType operationtype,
 
 			allow_undo( true ) ;
 			allow_apply( true ) ;
-	}
 
 			Refresh_Visual();
 			
@@ -639,6 +641,20 @@ void Win_GParted::Add_Operation( OperationType operationtype,
 			treeview_operations .set_cursor(
 				static_cast<Gtk::TreePath>( static_cast<Gtk::TreeRow>( 
 						*(--liststore_operations ->children() .end()) ) ) ) ;
+		}
+		else
+		{
+			Gtk::MessageDialog dialog( *this,
+				   _("Could not add this operation to the list."),
+				   false,
+				   Gtk::MESSAGE_ERROR,
+				   Gtk::BUTTONS_OK,
+				   true );
+			dialog .set_secondary_text( error ) ;
+
+			dialog .run() ;
+		}
+	}
 }
 
 void Win_GParted::Refresh_Visual()