patch 8.0.0474: the client-server feature is not tested

Problem:    The client-server feature is not tested.
Solution:   Add a test.

src/Makefile

@@ -2097,11 +2097,12 @@ test_arglist \
 	test_breakindent \
 	test_bufwintabinfo \
 	test_cdo \
+	test_changedtick \
 	test_channel \
 	test_charsearch \
 	test_charsearch_utf8 \
-	test_changedtick \
 	test_cindent \
+	test_clientserver \
 	test_cmdline \
 	test_command_count \
 	test_crypt \

src/os_mswin.c

@@ -2105,11 +2105,15 @@ Messaging_WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 
 	    str = serverConvert(client_enc, (char_u *)data->lpData, &tofree);
 	    res = eval_client_expr_to_string(str);
-	    vim_free(tofree);
 
 	    if (res == NULL)
 	    {
-		res = vim_strsave((char_u *)_(e_invexprmsg));
+		char	*err = _(e_invexprmsg);
+		size_t	len = STRLEN(str) + STRLEN(err) + 5;
+
+		res = alloc(len);
+		if (res != NULL)
+		    vim_snprintf((char *)res, len, "%s: \"%s\"", err, str);
 		reply.dwData = COPYDATA_ERROR_RESULT;
 	    }
 	    else
@@ -2120,6 +2124,7 @@ Messaging_WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 	    serverSendEnc(sender);
 	    retval = (int)SendMessage(sender, WM_COPYDATA,
 				    (WPARAM)message_window, (LPARAM)(&reply));
+	    vim_free(tofree);
 	    vim_free(res);
 	    return retval;
 

src/testdir/Make_all.mak

@@ -144,6 +144,7 @@ NEW_TESTS = test_arabic.res \
 	    test_channel.res \
 	    test_charsearch.res \
 	    test_cindent.res \
+	    test_clientserver.res \
 	    test_cmdline.res \
 	    test_command_count.res \
 	    test_crypt.res \

src/testdir/shared.vim

@@ -164,6 +164,22 @@ func s:feedkeys(timer)
   call feedkeys('x', 'nt')
 endfunc
 
+" Get the command to run Vim, with -u NONE and --not-a-term arguments.
+" Returns an empty string on error.
+func GetVimCommand()
+  if !filereadable('vimcmd')
+    return ''
+  endif
+  let cmd = readfile('vimcmd')[0]
+  let cmd = substitute(cmd, '-u \f\+', '-u NONE', '')
+  if cmd !~ '-u NONE'
+    let cmd = cmd . ' -u NONE'
+  endif
+  let cmd .= ' --not-a-term'
+  let cmd = substitute(cmd, 'VIMRUNTIME=.*VIMRUNTIME;', '', '')
+  return cmd
+endfunc
+
 " Run Vim, using the "vimcmd" file and "-u NORC".
 " "before" is a list of Vim commands to be executed before loading plugins.
 " "after" is a list of Vim commands to be executed after loading plugins.
@@ -174,7 +190,8 @@ func RunVim(before, after, arguments)
 endfunc
 
 func RunVimPiped(before, after, arguments, pipecmd)
-  if !filereadable('vimcmd')
+  let cmd = GetVimCommand()
+  if cmd == ''
     return 0
   endif
   let args = ''
@@ -187,18 +204,6 @@ func RunVimPiped(before, after, arguments, pipecmd)
     let args .= ' -S Xafter.vim'
   endif
 
-  let cmd = readfile('vimcmd')[0]
-  let cmd = substitute(cmd, '-u \f\+', '-u NONE', '')
-  if cmd !~ '-u NONE'
-    let cmd = cmd . ' -u NONE'
-  endif
-  let cmd .= ' --not-a-term'
-
-  " With pipecmd we can't set VIMRUNTIME.
-  if a:pipecmd != ''
-    let cmd = substitute(cmd, 'VIMRUNTIME=.*VIMRUNTIME;', '', '')
-  endif
-
   exe "silent !" . a:pipecmd . cmd . args . ' ' . a:arguments
 
   if len(a:before) > 0

src/testdir/test_clientserver.vim

@@ -0,0 +1,42 @@
+" Tests for the +clientserver feature.
+
+if !has('job') || !has('clientserver')
+  finish
+endif
+
+source shared.vim
+
+func Test_client_server()
+  let cmd = GetVimCommand()
+  if cmd == ''
+    return
+  endif
+  let name = 'XVIMTEXT'
+  let cmd .= ' --servername ' . name
+  let g:job = job_start(cmd, {'stoponexit': 'kill', 'out_io': 'null'})
+  call WaitFor('job_status(g:job) == "run"')
+  if job_status(g:job) != 'run'
+    call assert_true(0, 'Cannot run the Vim server')
+    return
+  endif
+
+  " Takes a short while for the server to be active.
+  call WaitFor('serverlist() =~ "' . name . '"')
+  call assert_match(name, serverlist())
+
+  call remote_foreground(name)
+
+  call remote_send(name, ":let testvar = 'yes'\<CR>")
+  call WaitFor('remote_expr("' . name . '", "testvar") == "yes"')
+  call assert_equal('yes', remote_expr(name, "testvar"))
+
+  call remote_send(name, ":qa!\<CR>")
+  call WaitFor('job_status(g:job) == "dead"')
+  if job_status(g:job) != 'dead'
+    call assert_true(0, 'Server did not exit')
+    call job_stop(g:job, 'kill')
+  endif
+endfunc
+
+" Uncomment this line to get a debugging log
+" call ch_logfile('channellog', 'w')

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    474,
 /**/
     473,
 /**/