#
#
# patch "lib/perl/Annotate.pm"
#  from [9a778d09c5f605b1795e81b05eb21f8feb4b1fb0]
#    to [91b47ddd78719db24155c0802848e2d1d63e3838]
# 
# patch "lib/perl/Common.pm"
#  from [d6df7409384166de94c655c2a24103ebdd33d4e2]
#    to [57dd6913d5e258aff37e2bb9601aa81e0572e950]
# 
# patch "lib/perl/History.pm"
#  from [7b9c9357c231510a04bb673b076cfbffc4fbb7a0]
#    to [8b821d263a1376c0b81ca75e31651494f4eb3fd4]
# 
# patch "lib/ui/mtn-browse.glade"
#  from [fba49e593b91f655d1edcbe681f8bdfe406cff19]
#    to [969d7bc6d90ed297737fa7c5fbf027a3c5200b34]
#
============================================================
--- lib/perl/Annotate.pm	9a778d09c5f605b1795e81b05eb21f8feb4b1fb0
+++ lib/perl/Annotate.pm	91b47ddd78719db24155c0802848e2d1d63e3838
@@ -810,7 +810,8 @@ sub mtn_annotate($$$$)
     my($buffer,
        @cmd,
        $cwd,
-       $exception);
+       $exception,
+       $ret_val);
 
     # Run mtn annotate in the root directory so as to avoid any workspace
     # conflicts.
@@ -826,7 +827,7 @@ sub mtn_annotate($$$$)
     eval
     {
 	die("chdir failed: " . $!) unless (chdir(File::Spec->rootdir()));
-	return unless (run_command(\$buffer, @cmd));
+	$ret_val = run_command(\$buffer, undef, @cmd);
     };
     $exception = $@;
     chdir($cwd);
@@ -850,7 +851,7 @@ sub mtn_annotate($$$$)
 
     @$list = split(/\n/, $buffer);
 
-    return 1;
+    return $ret_val;
 
 }
 
============================================================
--- lib/perl/Common.pm	d6df7409384166de94c655c2a24103ebdd33d4e2
+++ lib/perl/Common.pm	57dd6913d5e258aff37e2bb9601aa81e0572e950
@@ -89,7 +89,7 @@ sub register_help_callbacks($@);
 sub open_database($$$);
 sub program_valid($;$);
 sub register_help_callbacks($@);
-sub run_command($@);
+sub run_command($$@);
 sub save_as_file($$$);
 sub set_label_value($$);
 sub treeview_column_searcher($$$$);
@@ -154,6 +154,9 @@ sub generate_tmp_path($)
 #
 #   Data         - $buffer      : A reference to the buffer that is to contain
 #                                 the output from the command.
+#                  $abort       : Either a reference to a boolean that is set
+#                                 to true if the command is to be aborted or
+#                                 undef if no abort checking is required.
 #                  $args        : A list containing the command to run and its
 #                                 arguments.
 #                  Return Value : True if the command worked, otherwise false
@@ -163,12 +166,13 @@ sub generate_tmp_path($)
 
 
 
-sub run_command($@)
+sub run_command($$@)
 {
 
-    my($buffer, @args) = @_;
+    my($buffer, $abort, @args) = @_;
 
-    my(@err,
+    my($dummy_flag,
+       @err,
        $fd_err,
        $fd_in,
        $fd_out,
@@ -178,6 +182,8 @@ sub run_command($@)
        $total_bytes,
        $watcher);
 
+    $abort = \$dummy_flag unless (defined($abort));
+
     # Run the command.
 
     $fd_err = gensym();
@@ -225,7 +231,7 @@ sub run_command($@)
     # Setup a watch handler to read our data and handle GTK2 events whilst the
     # command is running.
 
-    $stop = $total_bytes = 0;
+    $total_bytes = 0;
     $$buffer = "";
     $watcher = Gtk2::Helper->add_watch
 	(fileno($fd_out), "in",
@@ -235,7 +241,8 @@ sub run_command($@)
 					$$buffer,
 					32768,
 					$total_bytes))
-		 == 0)
+		     == 0
+		 || ! defined($bytes_read))
 	     {
 		 $stop = 1;
 	     }
@@ -245,15 +252,23 @@ sub run_command($@)
 	     }
 	     return TRUE;
 	 });
-    while (! $stop)
+    while (! $stop && ! $$abort)
     {
 	Gtk2->main_iteration();
     }
     Gtk2::Helper->remove_watch($watcher);
 
-    # Get any error output.
+    # If we have been asked to abort then terminate the subprocess, otherwise
+    # get any error output as the subprocess has just exited of its own accord.
 
-    @err = readline($fd_err);
+    if ($$abort)
+    {
+	kill("TERM", $pid);
+    }
+    else
+    {
+	@err = readline($fd_err) unless ($$abort);
+    }
 
     close($fd_in);
     close($fd_out);
@@ -288,43 +303,47 @@ sub run_command($@)
 
 	if ($wait_status == $pid)
 	{
-	    my $exit_status = $?;
-	    if (WIFEXITED($exit_status) && WEXITSTATUS($exit_status) != 0)
+	    if (! $$abort)
 	    {
-		my $dialog = Gtk2::MessageDialog->new_with_markup
-		    (undef,
-		     ["modal"],
-		     "warning",
-		     "close",
-		     __x("The {name} subprocess failed with an exit status\n"
-			     . "of {exit_code} and printed the following on "
-			     . "stderr:\n"
-			     . "<b><i>{error_message}</i></b>",
-			 name => Glib::Markup::escape_text($args[0]),
-			 exit_code => WEXITSTATUS($exit_status),
-			 error_message => Glib::Markup::escape_text
-                                          (join("", @err))));
-		WindowManager->instance()->allow_input
-		    (sub { $dialog->run(); });
-		$dialog->destroy();
-		return;
+		my $exit_status = $?;
+		if (WIFEXITED($exit_status) && WEXITSTATUS($exit_status) != 0)
+		{
+		    my $dialog = Gtk2::MessageDialog->new_with_markup
+			(undef,
+			 ["modal"],
+			 "warning",
+			 "close",
+			 __x("The {name} subprocess failed with an exit "
+			         . "status\n"
+				 . "of {exit_code} and printed the following "
+			         . "on stderr:\n"
+				 . "<b><i>{error_message}</i></b>",
+			     name => Glib::Markup::escape_text($args[0]),
+			     exit_code => WEXITSTATUS($exit_status),
+			     error_message => Glib::Markup::escape_text
+					      (join("", @err))));
+		    WindowManager->instance()->allow_input
+			(sub { $dialog->run(); });
+		    $dialog->destroy();
+		    return;
+		}
+		elsif (WIFSIGNALED($exit_status))
+		{
+		    my $dialog = Gtk2::MessageDialog->new
+			(undef,
+			 ["modal"],
+			 "warning",
+			 "close",
+			 __x("The {name} subprocess was terminated by signal "
+				 . "{number}.",
+			     name   => Glib::Markup::escape_text($args[0]),
+			     number => WTERMSIG($exit_status)));
+		    WindowManager->instance()->allow_input
+			(sub { $dialog->run(); });
+		    $dialog->destroy();
+		    return;
+		}
 	    }
-	    elsif (WIFSIGNALED($exit_status))
-	    {
-		my $dialog = Gtk2::MessageDialog->new
-		    (undef,
-		     ["modal"],
-		     "warning",
-		     "close",
-		     __x("The {name} subprocess was terminated by signal "
-			     . "{number}.",
-			 name   => Glib::Markup::escape_text($args[0]),
-			 number => WTERMSIG($exit_status)));
-		WindowManager->instance()->allow_input
-		    (sub { $dialog->run(); });
-		$dialog->destroy();
-		return;
-	    }
 	    last;
 	}
 
============================================================
--- lib/perl/History.pm	7b9c9357c231510a04bb673b076cfbffc4fbb7a0
+++ lib/perl/History.pm	8b821d263a1376c0b81ca75e31651494f4eb3fd4
@@ -94,10 +94,10 @@ sub get_history_window();
 sub file_comparison_combobox_changed_cb($$);
 sub get_file_history_helper($$$);
 sub get_history_window();
-sub get_revision_comparison_window();
+sub get_revision_comparison_window($);
 sub get_revision_history_helper($$);
 sub history_list_button_clicked_cb($$);
-sub mtn_diff($$$$;$);
+sub mtn_diff($$$$$;$);
 sub save_differences_button_clicked_cb($$);
 #
 ##############################################################################
@@ -538,7 +538,7 @@ sub display_revision_comparison($$$;$)
        $iter);
     my $wm = WindowManager->instance();
 
-    $instance = get_revision_comparison_window();
+    $instance = get_revision_comparison_window($mtn);
     local $instance->{in_cb} = 1;
 
     $instance->{window}->
@@ -560,37 +560,77 @@ sub display_revision_comparison($$$;$)
 
     $wm->make_busy($instance, 1);
     $instance->{appbar}->push($instance->{appbar}->get_status()->get_text());
+    $instance->{stop_button}->set_sensitive(TRUE);
     $wm->update_gui();
 
     $instance->{mtn} = $mtn;
     $instance->{revision_id_1} = $revision_id_1;
     $instance->{revision_id_2} = $revision_id_2;
 
-    # Get Monotone to do the comparison.
+    # Get Monotone to do the comparison, later versions can do this via
+    # automate stdio.
 
     $instance->{appbar}->set_status(__("Calculating differences"));
     $wm->update_gui();
     if ($mtn->supports(MTN_CONTENT_DIFF_EXTRA_OPTIONS))
     {
+
+	my $exception;
+
+	local $instance->{kill_mtn_subprocess} = 1;
+
+	# The stop button callback will kill off the mtn subprocess so suppress
+	# any resultant errors.
+
 	$mtn->suppress_utf8_conversion(1);
-	$mtn->content_diff($instance->{diff_output},
-			   ["with-header"],
-			   $revision_id_1,
-			   $revision_id_2,
-			   $file_name);
+	CachingAutomateStdio->register_error_handler
+	    (MTN_SEVERITY_ALL,
+	     sub {
+		 my($severity, $message, $instance) = @_;
+		 mtn_error_handler($severity, $message)
+		     if ($severity == MTN_SEVERITY_WARNING
+			 || ! $instance->{stop});
+	     },
+	     $instance);
+	eval
+	{
+	    $mtn->content_diff($instance->{diff_output},
+			       ["with-header"],
+			       $revision_id_1,
+			       $revision_id_2,
+			       $file_name);
+	};
+	$exception = $@;
+	CachingAutomateStdio->register_error_handler(MTN_SEVERITY_ALL,
+						     \&mtn_error_handler);
 	$mtn->suppress_utf8_conversion(0);
+
+	# If we have aborted the comparison by killing off the mtn subprocess
+	# then cleanly closedown and restart it, otherwise rethrow any raised
+	# exceptions.
+
+	if ($instance->{stop})
+	{
+	    my $dummy;
+	    $mtn->closedown();
+	    $mtn->interface_version(\$dummy);
+	}
+	elsif ($exception)
+	{
+	    die($exception);
+	}
+
     }
     else
     {
 	mtn_diff($instance->{diff_output},
+		 \$instance->{stop},
 		 $mtn->get_db_name(),
 		 $revision_id_1,
 		 $revision_id_2,
 		 $file_name);
     }
 
-    $instance->{stop_button}->set_sensitive(TRUE);
-
     # Does the user want pretty printed differences output?
 
     if ($user_preferences->{coloured_diffs})
@@ -1751,16 +1791,20 @@ sub get_revision_history_helper($$)
 #   Description  - Creates or prepares an existing revision comparison window
 #                  for use.
 #
-#   Data         - Return Value : A reference to the newly created or unused
+#   Data         - $mtn         : The Monotone::AutomateStdio object that is
+#                                 to be used to do the comparison.
+#                  Return Value : A reference to the newly created or unused
 #                                 change log instance record.
 #
 ##############################################################################
 
 
 
-sub get_revision_comparison_window()
+sub get_revision_comparison_window($)
 {
 
+    my $mtn = $_[0];
+
     my($height,
        $instance,
        $renderer,
@@ -1821,8 +1865,24 @@ sub get_revision_comparison_window()
 		 return TRUE;
 	     },
 	     $instance);
-	$instance->{stop_button}->signal_connect
-	    ("clicked", sub { $_[1]->{stop} = 1; }, $instance);
+	if ($mtn->supports(MTN_CONTENT_DIFF_EXTRA_OPTIONS))
+	{
+	    $instance->{kill_mtn_subprocess} = 0;
+	    $instance->{stop_button}->signal_connect
+		("clicked",
+		 sub {
+		     my($widget, $instance) = @_;
+		     $instance->{stop} = 1;
+		     kill("TERM", $instance->{mtn}->get_pid())
+			 if ($instance->{kill_mtn_subprocess});
+		 },
+		 $instance);
+	}
+	else
+	{
+	    $instance->{stop_button}->signal_connect
+		("clicked", sub { $_[1]->{stop} = 1; }, $instance);
+	}
 
 	# Setup the file combobox.
 
@@ -2045,6 +2105,9 @@ sub external_diffs($$$$$$)
 #
 #   Data         - $list          : A reference to the list that is to contain
 #                                   the output from the diff command.
+#                  $abort         : A reference to an abort flag that when
+#                                   true will cause the mtn diff process to
+#                                   stop.
 #                  $mtn_db        : The Monotone database that is to be used
 #                                   or undef if the database associated with
 #                                   the current workspace is to be used.
@@ -2063,15 +2126,21 @@ sub external_diffs($$$$$$)
 
 
 
-sub mtn_diff($$$$;$)
+sub mtn_diff($$$$$;$)
 {
 
-    my($list, $mtn_db, $revision_id_1, $revision_id_2, $file_name) = @_;
+    my($list,
+       $abort,
+       $mtn_db,
+       $revision_id_1,
+       $revision_id_2,
+       $file_name) = @_;
 
     my($buffer,
        @cmd,
        $cwd,
-       $exception);
+       $exception,
+       $ret_val);
 
     # Run mtn diff in the root directory so as to avoid any workspace
     # conflicts.
@@ -2089,32 +2158,40 @@ sub mtn_diff($$$$;$)
     eval
     {
 	die("chdir failed: " . $!) unless (chdir(File::Spec->rootdir()));
-	return unless (run_command(\$buffer, @cmd));
+	$ret_val = run_command(\$buffer, $abort, @cmd);
     };
     $exception = $@;
     chdir($cwd);
-    if ($exception)
+    if (! $$abort)
     {
-	my $dialog = Gtk2::MessageDialog->new_with_markup
-	    (undef,
-	     ["modal"],
-	     "warning",
-	     "close",
-	     __x("Problem running mtn diff, got:\n"
-		     . "<b><i>{error_message}</i></b>\n"
-		     . "This should not be happening!",
-		 error_message => Glib::Markup::escape_text($exception)));
-	WindowManager->instance()->allow_input(sub { $dialog->run(); });
-	$dialog->destroy();
-	return;
-    }
+	if ($exception)
+	{
+	    my $dialog = Gtk2::MessageDialog->new_with_markup
+		(undef,
+		 ["modal"],
+		 "warning",
+		 "close",
+		 __x("Problem running mtn diff, got:\n"
+		         . "<b><i>{error_message}</i></b>\n"
+		         . "This should not be happening!",
+		     error_message => Glib::Markup::escape_text($exception)));
+	    WindowManager->instance()->allow_input(sub { $dialog->run(); });
+	    $dialog->destroy();
+	    return;
+	}
 
-    # Break up the input into a list of lines.
+	# Break up the input into a list of lines.
 
-    @$list = split(/\n/, $buffer);
+	@$list = split(/\n/, $buffer);
 
-    return 1;
+    }
+    else
+    {
+	@$list = ();
+    }
 
+    return $ret_val;
+
 }
 
 1;
============================================================
--- lib/ui/mtn-browse.glade	fba49e593b91f655d1edcbe681f8bdfe406cff19
+++ lib/ui/mtn-browse.glade	969d7bc6d90ed297737fa7c5fbf027a3c5200b34
@@ -3690,8 +3690,8 @@ Tag</property>
 			  <child>
 			    <widget class="GtkEventBox" id="revision_id_1_label_eventbox">
 			      <property name="visible">True</property>
-			      <property name="tooltip" translatable="yes">Revision id of the first selected
-file version that is to be compared</property>
+			      <property name="tooltip" translatable="yes">The first of two revision ids
+selected for comparison</property>
 			      <property name="visible_window">True</property>
 			      <property name="above_child">False</property>
 
@@ -3724,8 +3724,8 @@ file version that is to be compared</pro
 			  <child>
 			    <widget class="GtkEventBox" id="revision_id_2_label_eventbox">
 			      <property name="visible">True</property>
-			      <property name="tooltip" translatable="yes">Revision id of the second selected
-file version that is to be compared</property>
+			      <property name="tooltip" translatable="yes">The second of two revision
+ids selected for comparison</property>
 			      <property name="visible_window">True</property>
 			      <property name="above_child">False</property>
 
@@ -4038,7 +4038,7 @@ selected file in an external viewer</pro
 			    <widget class="GtkButton" id="stop_button">
 			      <property name="visible">True</property>
 			      <property name="sensitive">False</property>
-			      <property name="tooltip" translatable="yes">Stop formatting the comparison results</property>
+			      <property name="tooltip" translatable="yes">Stop the comparison</property>
 			      <property name="can_focus">True</property>
 			      <property name="relief">GTK_RELIEF_NONE</property>
 			      <property name="focus_on_click">False</property>