patch 8.1.0799: calling deleted function; test doesn't work on Mac

Problem:    Calling deleted function; test doesn't work on Mac.
Solution:   Wait for the function to be called before deleting it. Use a job
            to write to the pty, unless in the GUI. (Ozaki Kiichi,
            closes #3854)

src/testdir/test_channel.vim

@@ -1945,10 +1945,11 @@ func Test_job_start_in_timer()
   endif
 
   func OutCb(chan, msg)
+    let g:val += 1
   endfunc
 
   func ExitCb(job, status)
-    let g:val = 1
+    let g:val += 1
     call Resume()
   endfunc
 
@@ -1967,6 +1968,10 @@ func Test_job_start_in_timer()
   call timer_start(1, 'TimerCb')
   let elapsed = Standby(&ut)
   call assert_inrange(1, &ut / 2, elapsed)
+
+  " Wait for both OutCb() and ExitCb() to have been called before deleting
+  " them.
+  call WaitForAssert({-> assert_equal(2, g:val)})
   call job_stop(g:job)
 
   delfunc OutCb

src/testdir/test_terminal.vim

@@ -643,19 +643,17 @@ func Test_terminal_write_stdin()
 endfunc
 
 func Test_terminal_no_cmd()
-  " Does not work on Mac.
-  if has('mac')
-    return
-  endif
   let buf = term_start('NONE', {})
   call assert_notequal(0, buf)
 
   let pty = job_info(term_getjob(buf))['tty_out']
   call assert_notequal('', pty)
-  if has('win32')
+  if has('gui_running') && !has('win32')
-    silent exe '!start cmd /c "echo look here > ' . pty . '"'
+    " In the GUI job_start() doesn't work, it does not read from the pty.
-  else
     call system('echo "look here" > ' . pty)
+  else
+    " Otherwise using a job works on all systems.
+    call job_start([&shell, &shellcmdflag, 'echo "look here" > ' . pty])
   endif
   call WaitForAssert({-> assert_match('look here', term_getline(buf, 1))})
 

src/version.c

@@ -791,6 +791,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    799,
 /**/
     798,
 /**/