luatelnet: accept multiple commands seperated by '\n' or '\r'.

It was possible with the oldtelnet interface using something like
(echo admin ; echo help) | nc localhost 4212
That's now working with the lua one (but not the cleanest way).
(cherry picked from commit f5b8b43a)
Signed-off-by: Rémi Duraffort <ivoire@videolan.org>

share/lua/intf/telnet.lua

@@ -183,27 +183,49 @@ while not vlc.misc.should_die() do
 
     -- Handle reads
     for _, client in pairs(r) do
-        local str = client:recv(1000)
+        local str = string.gsub(client:recv(1000),"\r","\n")
         local done = false
-        if not str then -- the telnet client program has leave
+
+        -- the telnet client program has leave
+        if not str then
             client.buffer = "quit"
             done = true
-        elseif string.match(str,"\n$") then
-            client.buffer = string.gsub(client.buffer..str,"\r?\n$","")
-            done = true
+
+        -- Caught a ^D
         elseif client.buffer == ""
            and ((client.type == host.client_type.stdio and str == "")
            or  (client.type == host.client_type.net and str == "\004")) then
-            -- Caught a ^D
             client.buffer = "quit"
             done = true
+
+        -- '\n' found: a command was sent
+        elseif string.match(str,"\n") then
+            client.buffer = client.buffer .. str
+            done = true
+
+        -- The command is not finished yet
         else
             client.buffer = client.buffer .. str
         end
+
+        -- Some cleaning for telnet
         if client.type == host.client_type.net then
             telnet_commands( client )
         end
+
+        -- If a command must be parsed
         if done then
+            -- loop on all commands (might have more than one commands seperated by '\n'
+            local returned_values = ""
+            while not (client.buffer == "") do
+                -- pick the first command
+                local commands = ""
+                if string.find(client.buffer, "\n") then
+                    commands = string.sub(client.buffer, string.find(client.buffer, "\n") + 1)
+                    client.buffer = string.sub(client.buffer, 0, string.find(client.buffer, "\n") - 1)
+                end
+                local cmd = client.buffer
+
                 if client.status == host.status.password then
                     if client.buffer == password then
                         client:send( IAC..WONT..ECHO.."\r\nWelcome, Master\r\n" )
@@ -215,7 +237,14 @@ while not vlc.misc.should_die() do
                     end
                 elseif client_command( client ) then
                     client:switch_status( host.status.write )
+                    -- special case to exit the loop
+                    if cmd == "quit" or cmd == "shutdown" then break end
+                end
+                returned_values = returned_values .. client.buffer
+                client.buffer = commands
             end
+            vlc.msg.err("end of loop")
+            client.buffer = returned_values
         end
     end
 end