Process error directives during download

lib/net/scp.rb

@@ -128,6 +128,11 @@ module Net
   # * E -- terminator directive. Indicates the end of a directory, and subsequent
   #   files and directories should be received by the parent of the current
   #   directory.
+  # * \0 -- indicates a successful response from the other end.
+  # * \1 -- warning directive. Indicates a warning from the other end.  Text from
+  #   this warning will be reported if the SCP results in an error.
+  # * \2 -- error directive.  Indicates an error from the other end.  Text from
+  #   this error will be reported if the SCP results in an error.
   #
   # If a 'C' directive is received, we switch over to
   # Net::SCP::Download#read_data_state. If an 'E' directive is received, and
@@ -355,8 +360,9 @@ def start_command(mode, local, remote, options={}, &callback)
               channel[:buffer  ] = Net::SSH::Buffer.new
               channel[:state   ] = "#{mode}_start"
               channel[:stack   ] = []
+              channel[:error_string] = ''
 
-              channel.on_close                  { |ch| raise Net::SCP::Error, "SCP did not finish successfully (#{ch[:exit]})" if ch[:exit] != 0 }
+              channel.on_close                  { |ch| send("#{channel[:state]}_state", channel); raise Net::SCP::Error, "SCP did not finish successfully (#{channel[:exit]}): #{channel[:error_string]}" if channel[:exit] != 0 }
               channel.on_data                   { |ch, data| channel[:buffer].append(data) }
               channel.on_extended_data          { |ch, type, data| debug { data.chomp } }
               channel.on_request("exit-status") { |ch, data| channel[:exit] = data.read_long }

lib/net/scp/download.rb

@@ -37,7 +37,13 @@ def read_directive_state(channel)
 
       directive = parse_directive(line)
       case directive[:type]
-      when :times then
+      when :OK
+        return
+      when :warning
+        channel[:error_string] << directive[:message]
+      when :error
+        channel[:error_string] << directive[:message]
+      when :times
         channel[:times] = directive
       when :directory
         read_directory(channel, directive)
@@ -87,6 +93,15 @@ def finish_read_state(channel)
     # data.
     def parse_directive(text)
       case type = text[0]
+      when "\x00"
+        # Success
+        { :type => :OK }
+      when "\x01"
+        { :type => :warning,
+          :message => text[1..-1] }
+      when "\x02"
+        { :type => :error,
+          :message => text[1..-1] }
       when ?T
         parts = text[1..-1].split(/ /, 4).map { |i| i.to_i }
         { :type  => :times,

test/test_download.rb

@@ -54,6 +54,33 @@ def test_download_with_preserve_should_send_times
     assert_equal "a" * 1234, file.io.string
   end
 
+  def test_download_with_error_should_respond_with_error_text
+    story do |session|
+      channel = session.opens_channel
+      channel.sends_exec "scp -f /path/to/remote.txt"
+
+      channel.sends_ok
+      channel.gets_data "\x01File not found: /path/to/remote.txt\n"
+      channel.sends_ok
+
+      channel.gets_eof
+      channel.gets_exit_status(1)
+      channel.gets_close
+      channel.sends_close
+    end
+
+    error = nil
+    assert_scripted do
+      begin
+        scp.download!("/path/to/remote.txt")
+      rescue
+        error = $!
+      end
+    end
+    assert_equal Net::SCP::Error, error.class
+    assert_equal "SCP did not finish successfully (1): File not found: /path/to/remote.txt\n", error.message
+  end
+
   def test_download_with_progress_callback_should_invoke_callback
     prepare_file("/path/to/local.txt", "a" * 3000 + "b" * 3000 + "c" * 3000 + "d" * 3000)