Use TERM env var / terminfo to decide whether to send ECH. Fixes tmux bug.

Closes #28 github issue.

README.md

@@ -88,6 +88,7 @@ Getting Mosh
   * [GNU Autotools][]
   * the [Protocol Buffers][] library and compiler
   * [Boost][]
+  * `ncurses`
   * `libutempter`
   * `zlib`
   * the Perl module [IO::Pty][]

configure.ac

@@ -75,7 +75,7 @@ AS_IF([test x"$with_skalibs" != xno],
    AC_SUBST([STDDJB_LDFLAGS], ["$SKALIBS_LDFLAGS -lstddjb"])])
 
 # Checks for header files.
-AC_CHECK_HEADERS([arpa/inet.h fcntl.h langinfo.h limits.h locale.h netinet/in.h pty.h stddef.h stdint.h stdlib.h string.h sys/ioctl.h sys/socket.h sys/time.h termios.h unistd.h util.h wchar.h wctype.h])
+AC_CHECK_HEADERS([arpa/inet.h curses.h fcntl.h langinfo.h limits.h locale.h netinet/in.h pty.h stddef.h stdint.h stdlib.h string.h sys/ioctl.h sys/socket.h sys/time.h term.h termios.h unistd.h util.h wchar.h wctype.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_HEADER_STDBOOL
@@ -99,6 +99,8 @@ AC_CHECK_FUNCS([gettimeofday inet_ntoa iswprint memchr memset nl_langinfo setenv
 
 AC_SEARCH_LIBS([clock_gettime], [rt], [AC_DEFINE([HAVE_CLOCK_GETTIME], [1], [Define if clock_gettime is available.])])
 
+AC_CHECK_LIB([ncurses], [setupterm])
+
 AC_CHECK_DECL([mach_absolute_time],
   [AC_DEFINE([HAVE_MACH_ABSOLUTE_TIME], [1],
      [Define if mach_absolute_time is available.])],

debian/control

@@ -2,7 +2,7 @@ Source: mosh
 Section: net
 Priority: optional
 Maintainer: Keith Winstein <keithw@mit.edu>
-Build-Depends: debhelper (>= 7.0.50), autotools-dev, protobuf-compiler, libprotobuf-dev, dh-autoreconf, pkg-config, libutempter-dev, libboost-dev, zlib1g-dev, skalibs-dev
+Build-Depends: debhelper (>= 7.0.50), autotools-dev, protobuf-compiler, libprotobuf-dev, dh-autoreconf, pkg-config, libutempter-dev, libboost-dev, zlib1g-dev, skalibs-dev, libncurses5-dev
 Standards-Version: 3.9.3
 Homepage: http://mosh.mit.edu
 Vcs-Git: git://github.com/keithw/mosh.git

src/examples/termemu.cc

@@ -148,7 +148,8 @@ int main( void )
 }
 
 /* Print a frame if the last frame was more than 1/50 seconds ago */
-bool tick( Terminal::Framebuffer &state, const Terminal::Framebuffer &new_frame )
+bool tick( Terminal::Framebuffer &state, const Terminal::Framebuffer &new_frame,
+	   const Terminal::Display &display )
 {
   static bool initialized = false;
   static struct timeval last_time;
@@ -164,7 +165,7 @@ bool tick( Terminal::Framebuffer &state, const Terminal::Framebuffer &new_frame
 
   if ( (!initialized)
        || (diff >= 0.02) ) {
-    std::string update = Terminal::Display::new_frame( initialized, state, new_frame );
+    std::string update = display.new_frame( initialized, state, new_frame );
     swrite( STDOUT_FILENO, update.c_str() );
     state = new_frame;
 
@@ -222,6 +223,9 @@ void emulate_terminal( int fd )
   Terminal::Complete complete( window_size.ws_col, window_size.ws_row );
   Terminal::Framebuffer state( window_size.ws_col, window_size.ws_row );
 
+  /* open display */
+  Terminal::Display display( true ); /* use TERM to initialize */
+
   struct pollfd pollfds[ 3 ];
 
   pollfds[ 0 ].fd = STDIN_FILENO;
@@ -310,14 +314,14 @@ void emulate_terminal( int fd )
       break;
     }
 
-    if ( tick( state, complete.get_fb()) ) { /* there was a frame */
+    if ( tick( state, complete.get_fb(), display ) ) { /* there was a frame */
       poll_timeout = -1;
     } else {
       poll_timeout = 20;
     }
   }
 
-  std::string update = Terminal::Display::new_frame( true, state, complete.get_fb() );
+  std::string update = display.new_frame( true, state, complete.get_fb() );
   swrite( STDOUT_FILENO, update.c_str() );
 
   swrite( STDOUT_FILENO, Terminal::Emulator::close().c_str() );

src/frontend/mosh-client.cc

@@ -89,6 +89,8 @@ int main( int argc, char *argv[] )
   } catch ( Crypto::CryptoException e ) {
     fprintf( stderr, "Crypto exception: %s\r\n",
 	     e.text.c_str() );
+  } catch ( std::string s ) {
+    fprintf( stderr, "Error: %s\r\n", s.c_str() );
   }
 
   printf( "\n[mosh is exiting.]\n" );

src/frontend/stmclient.cc

@@ -130,7 +130,7 @@ void STMClient::main_init( void )
   local_framebuffer = new Terminal::Framebuffer( window_size.ws_col, window_size.ws_row );
 
   /* initialize screen */
-  string init = Terminal::Display::new_frame( false, *local_framebuffer, *local_framebuffer );
+  string init = display.new_frame( false, *local_framebuffer, *local_framebuffer );
   swrite( STDOUT_FILENO, init.data(), init.size() );
 
   /* open network */
@@ -158,9 +158,9 @@ void STMClient::output_new_frame( void )
   overlays.apply( new_state );
 
   /* calculate minimal difference from where we are */
-  const string diff( Terminal::Display::new_frame( !repaint_requested,
+  const string diff( display.new_frame( !repaint_requested,
-						   *local_framebuffer,
+					*local_framebuffer,
-						   new_state ) );
+					new_state ) );
   swrite( STDOUT_FILENO, diff.data(), diff.size() );
   *local_framebuffer = new_state;
 

src/frontend/stmclient.h

@@ -42,6 +42,7 @@ private:
   Terminal::Framebuffer *local_framebuffer;
   Overlay::OverlayManager overlays;
   Network::Transport< Network::UserStream, Terminal::Complete > *network;
+  Terminal::Display display;
 
   bool repaint_requested, quit_sequence_started;
 
@@ -61,6 +62,7 @@ public:
       local_framebuffer( NULL ),
       overlays(),
       network( NULL ),
+      display( true ), /* use TERM environment var to initialize display */
       repaint_requested( false ),
       quit_sequence_started( false )
   {

src/statesync/completeterminal.cc

@@ -75,7 +75,7 @@ string Complete::diff_from( const Complete &existing ) const
       new_res->MutableExtension( resize )->set_height( terminal.get_fb().ds.get_height() );
     }
     Instruction *new_inst = output.add_instruction();
-    new_inst->MutableExtension( hostbytes )->set_hoststring( Terminal::Display::new_frame( true, existing.get_fb(), terminal.get_fb() ) );
+    new_inst->MutableExtension( hostbytes )->set_hoststring( display.new_frame( true, existing.get_fb(), terminal.get_fb() ) );
   }
   
   return output.SerializeAsString();

src/statesync/completeterminal.h

@@ -32,6 +32,7 @@ namespace Terminal {
   private:
     Parser::UTF8Parser parser;
     Terminal::Emulator terminal;
+    Terminal::Display display;
 
     std::list< std::pair<uint64_t, uint64_t> > input_history;
     uint64_t echo_ack;
@@ -39,7 +40,7 @@ namespace Terminal {
     static const int ECHO_TIMEOUT = 50; /* for late ack */
 
   public:
-    Complete( size_t width, size_t height ) : parser(), terminal( width, height ),
+    Complete( size_t width, size_t height ) : parser(), terminal( width, height ), display( false ),
 					      input_history(), echo_ack( 0 ) {}
     
     std::string act( const std::string &str );

src/terminal/Makefile.am

@@ -3,5 +3,4 @@ AM_CXXFLAGS = $(WARNING_CXXFLAGS) $(PICKY_CXXFLAGS) -fno-default-inline -pipe
 
 noinst_LIBRARIES = libmoshterminal.a
 
-libmoshterminal_a_SOURCES = parseraction.cc parseraction.h parser.cc parser.h parserstate.cc parserstatefamily.h parserstate.h parsertransition.h terminal.cc terminaldispatcher.cc terminaldispatcher.h terminaldisplay.cc terminaldisplay.h terminalframebuffer.cc terminalframebuffer.h terminalfunctions.cc terminal.h terminaluserinput.cc terminaluserinput.h
+libmoshterminal_a_SOURCES = parseraction.cc parseraction.h parser.cc parser.h parserstate.cc parserstatefamily.h parserstate.h parsertransition.h terminal.cc terminaldispatcher.cc terminaldispatcher.h terminaldisplay.cc terminaldisplayinit.cc terminaldisplay.h terminalframebuffer.cc terminalframebuffer.h terminalfunctions.cc terminal.h terminaluserinput.cc terminaluserinput.h
-

src/terminal/terminaldisplay.cc

@@ -25,7 +25,7 @@ using namespace Terminal;
 
 /* Print a new "frame" to the terminal, using ANSI/ECMA-48 escape codes. */
 
-std::string Display::new_frame( bool initialized, const Framebuffer &last, const Framebuffer &f )
+std::string Display::new_frame( bool initialized, const Framebuffer &last, const Framebuffer &f ) const
 {
   FrameState frame( last );
 
@@ -201,7 +201,7 @@ std::string Display::new_frame( bool initialized, const Framebuffer &last, const
   return frame.str;
 }
 
-void Display::put_cell( bool initialized, FrameState &frame, const Framebuffer &f )
+void Display::put_cell( bool initialized, FrameState &frame, const Framebuffer &f ) const
 {
   char tmp[ 64 ];
 
@@ -238,13 +238,28 @@ void Display::put_cell( bool initialized, FrameState &frame, const Framebuffer &
       }
     }
 
-    frame.x += clear_count;
+    assert( frame.x + clear_count <= f.ds.get_width() );
-    if ( frame.x >= f.ds.get_width() ) {
+
+    /* can we go to the end of the line? */
+    if ( frame.x + clear_count == f.ds.get_width() ) {
       snprintf( tmp, 64, "\033[K" );
+      frame.append( tmp );
+      frame.x += clear_count;
     } else {
-      snprintf( tmp, 64, "\033[%dX", clear_count );
+      if ( has_ech ) {
+	if ( clear_count == 1 ) {
+	  frame.append( "\033[X" );
+	} else {
+	  snprintf( tmp, 64, "\033[%dX", clear_count );
+	  frame.append( tmp );
+	}
+	frame.x += clear_count;
+      } else { /* no ECH, so just print a space */
+	frame.append( " " );
+	frame.cursor_x++;
+	frame.x++;
+      }
     }
-    frame.append( tmp );
 
     return;
   }

src/terminal/terminaldisplay.h

@@ -49,10 +49,15 @@ namespace Terminal {
 
   class Display {
   private:
-    static void put_cell( bool initialized, FrameState &frame, const Framebuffer &f );
+    bool has_ech; /* erase character is part of vt200 but not supported by tmux
+		     (or by "screen" terminfo entry, which is what tmux advertises) */
+
+    void put_cell( bool initialized, FrameState &frame, const Framebuffer &f ) const;
 
   public:
-    static std::string new_frame( bool initialized, const Framebuffer &last, const Framebuffer &f );
+    std::string new_frame( bool initialized, const Framebuffer &last, const Framebuffer &f ) const;
+
+    Display( bool use_environment );
   };
 }
 

src/terminal/terminaldisplayinit.cc

@@ -0,0 +1,60 @@
+/*
+    Mosh: the mobile shell
+    Copyright 2012 Keith Winstein
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* This is in its own file because otherwise the ncurses #defines
+   alias our own variable names. */
+
+#include "terminaldisplay.h"
+
+#include <string>
+
+#include <curses.h>
+#include <term.h>
+
+using namespace Terminal;
+
+Display::Display( bool use_environment )
+  : has_ech( true )
+{
+  if ( use_environment ) {
+    int errret = -2;
+    int ret = setupterm( (char *)0, 1, &errret );
+
+    if ( ret != OK ) {
+      switch ( errret ) {
+      case 1:
+	throw std::string( "Terminal is hardcopy and cannot be used by curses applications." );
+	break;
+      case 0:
+	throw std::string( "Unknown terminal type." );
+	break;
+      case -1:
+	throw std::string( "Terminfo database could not be found." );
+	break;
+      default:
+	throw std::string( "Unknown terminfo error." );
+	break;
+      } 
+    }
+
+    char *val = tigetstr( "ech" );
+    if ( val <= 0 ) {
+      has_ech = false;
+    }
+  }
+}