commit d97fbf171ec0e63117813da045d2a1c51a9b6f62
author Bram Moolenaar <Bram@vim.org> Thu Nov 02 19:23:03 2017 +0100
committer Bram Moolenaar <Bram@vim.org> Thu Nov 02 19:23:03 2017 +0100
tree 50950cc1dda05d7b60097ab565fca41c2a63a724
parent f8f8b2eadbaf3090fcfccbab560de5dbd501833d

patch 8.0.1251: invalid expressin passed to WaitFor()

Problem:    Invalid expressin passed to WaitFor().
Solution:   Check if the variable exists.

src/testdir/test_clientserver.vim

diff --git a/src/testdir/test_clientserver.vim b/src/testdir/test_clientserver.vim
index 811af13..02840de 100644
--- a/src/testdir/test_clientserver.vim
+++ b/src/testdir/test_clientserver.vim
@@ -42,7 +42,7 @@
   call remote_foreground(name)
 
   call remote_send(name, ":let testvar = 'yes'\<CR>")
-  call WaitFor('remote_expr("' . name . '", "testvar", "", 1) == "yes"')
+  call WaitFor('remote_expr("' . name . '", "exists(\"testvar\") ? testvar : \"\"", "", 1) == "yes"')
   call assert_equal('yes', remote_expr(name, "testvar", "", 2))
 
   if has('unix') && has('gui') && !has('gui_running')