Support of close channel without exit-status

And new test - download interrupted

Author: robertcheramy

lib/net/scp.rb

@@ -363,16 +363,19 @@ def start_command(mode, local, remote, options={}, &callback)
               channel[:error_string] = ''
 
               channel.on_close do
-                if channel[:exit].nil? && channel[:state] == :finish
-                  # The remote closed the channel without sending an eof, but
-                  # the transfer was successful, so whe set channel[:exit] to 0
-                  channel[:exit] = 0
-                end
-                send("#{channel[:state]}_state", channel)
-                if channel[:exit] != 0
+                # If we got an exit-status and it is not 0, something went wrong
+                if !channel[:exit].nil? && channel[:exit] != 0
                   raise Net::SCP::Error, 'SCP did not finish successfully ' \
                                          "(#{channel[:exit]}): #{channel[:error_string]}"
                 end
+                # We may get no exit-status at all as returning a status is only RECOMENDED
+                # in RFC4254. But if our state is not :finish, something went wrong
+                if channel[:exit].nil? && channel[:state] != :finish
+                  raise Net::SCP::Error, 'SCP did not finish successfully ' \
+                                         '(channel closed before end of transmission)'
+                end
+                # At this point, :state can be :finish or :next_item
+                send("#{channel[:state]}_state", channel)
               end
               channel.on_data                   { |ch2, data| channel[:buffer].append(data) }
               channel.on_extended_data          { |ch2, type, data| debug { data.chomp } }

test/test_download.rb

@@ -225,16 +225,16 @@ def test_download_directory_should_create_directory_and_files_locally
     assert_equal "a" * 1234, file.io.string
   end
 
-  def test_download_should_work_when_remote_closes_channel_without_eof
+  def test_download_should_work_when_remote_closes_channel_without_exit_status
     file = prepare_file('/path/to/local.txt', 'a' * 1234)
 
     story do |session|
       channel = session.opens_channel
       channel.sends_exec 'scp -f /path/to/remote.txt'
       simple_download(channel)
-      # Remote closes without sending an eof
+      # Remote closes without sending an exit-status
       channel.gets_close
-      # We are polite and send an eof & close the channel
+      # We just send eof and close the channel
       channel.sends_eof
       channel.sends_close
     end
@@ -243,6 +243,35 @@ def test_download_should_work_when_remote_closes_channel_without_eof
     assert_equal 'a' * 1234, file.io.string
   end
 
+  def test_download_should_raise_error_when_remote_closes_channel_before_end
+    file = prepare_file('/path/to/local.txt', 'a' * 1234)
+
+    story do |session|
+      channel = session.opens_channel
+      channel.sends_exec 'scp -f /path/to/remote.txt'
+      channel.sends_ok
+      channel.gets_data "C%04o 1234 remote.txt\n" % 0666
+      channel.sends_ok
+      channel.gets_data 'a' * 500
+      # We should have received 1234 bytes and \0 but remote closed before the end
+      channel.gets_close
+      # We just send eof and close the channel
+      channel.sends_eof
+      channel.sends_close
+    end
+
+    error = nil
+    begin
+      assert_scripted { scp.download!('/path/to/remote.txt', '/path/to/local.txt') }
+    rescue => e
+      error = e
+    end
+
+    assert_equal Net::SCP::Error, error.class
+    assert_equal 'SCP did not finish successfully (channel closed before end of transmission)',
+        error.message
+  end
+
   private
 
     def simple_download(channel, mode=0666)