Avoid glibmm GSource bug/crash (again) (#697727)

The previous commit missed one glibmm GSource wrapper in the form of the
io watch for the PipeCapture class.  Convert this one to use glib
directly as well.

Bug #697727 - Segfault in livecd Gparted v 0.15.0-3 when copying
              partition

include/PipeCapture.h

@@ -31,11 +31,14 @@ class PipeCapture
 	unsigned int backcount;
 	unsigned int linelength;
 	Glib::RefPtr<Glib::IOChannel> channel;
-	sigc::connection connection;
+	guint sourceid;
 	bool OnReadable( Glib::IOCondition condition );
+	static gboolean _OnReadable( GIOChannel *source,
+	                             GIOCondition condition,
+	                             gpointer data );
 public:
 	PipeCapture( int fd, Glib::ustring &buffer );
-	void connect_signal( int fd );
+	void connect_signal();
 	~PipeCapture();
 	sigc::signal<void> eof;
 	sigc::signal<void> update;

src/FileSystem.cc

@@ -124,8 +124,8 @@ int FileSystem::execute_command( const Glib::ustring & command, OperationDetail
 	errorcapture.update.connect( sigc::bind( sigc::ptr_fun( relay_update ),
 						 &(children[children.size() - 1]),
 						 &error ) );
-	outputcapture.connect_signal( out );
-	errorcapture.connect_signal( err );
+	outputcapture.connect_signal();
+	errorcapture.connect_signal();
 
 	operationdetail.get_last_child().signal_cancel.connect(
 		sigc::bind(

src/PipeCapture.cc

@@ -20,22 +20,31 @@
 
 namespace GParted {
 
-PipeCapture::PipeCapture( int fd, Glib::ustring &string ) : buff( string ), backcount( 0 ), linelength( 0 )
+PipeCapture::PipeCapture( int fd, Glib::ustring &string ) : buff( string ), backcount( 0 ), linelength( 0 ),
+                                                            sourceid( 0 )
 {
 	// tie fd to string
 	// make channel
 	channel = Glib::IOChannel::create_from_fd( fd );
 }
 
-void PipeCapture::connect_signal( int fd )
+void PipeCapture::connect_signal()
 {
 	// connect handler to signal input/output
-	connection = Glib::signal_io().connect(
-		sigc::mem_fun( *this, &PipeCapture::OnReadable ),
-		fd,
-		Glib::IO_IN | Glib::IO_HUP | Glib::IO_ERR );
+	sourceid = g_io_add_watch( channel->gobj(),
+	                           GIOCondition(G_IO_IN | G_IO_ERR | G_IO_HUP),
+	                           _OnReadable,
+	                           this );
 }
 
+gboolean PipeCapture::_OnReadable( GIOChannel *source,
+				   GIOCondition condition,
+				   gpointer data )
+{
+	return static_cast<PipeCapture *>(data)->OnReadable( Glib::IOCondition(condition) );
+}
+
+
 bool PipeCapture::OnReadable( Glib::IOCondition condition )
 {
 	// read from pipe and store in buff
@@ -71,14 +80,14 @@ bool PipeCapture::OnReadable( Glib::IOCondition condition )
 	if (status != Glib::IO_STATUS_EOF)
 		std::cerr << "Pipe IOChannel read failed" << std::endl;
 	// signal completion
-	connection.disconnect();
 	eof();
 	return false;
 }
 
 PipeCapture::~PipeCapture()
 {
-	connection.disconnect();
+	if( sourceid > 0 )
+		g_source_remove( sourceid );
 }
 
 } // namespace GParted

src/Utils.cc

@@ -501,8 +501,8 @@ int Utils::execute_command( const Glib::ustring & command,
 		 status, &utils_execute_command_status::execute_command_eof ));
 	errorcapture.eof.connect( sigc::mem_fun(
 		 status, &utils_execute_command_status::execute_command_eof ));
-	outputcapture.connect_signal( out );
-	errorcapture.connect_signal( err );
+	outputcapture.connect_signal();
+	errorcapture.connect_signal();
 
 	if( status.foreground)
 		Gtk::Main::run();