patch 8.0.0539: startup test fails on Mac

Problem:    Startup test fails on Mac.
Solution:   Use another term name, "unknown" is known. Avoid a 2 second delay.
diff --git a/src/main.c b/src/main.c
index 78b6122..e3db0b2 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1013,6 +1013,15 @@
 }
 
 /*
+ * Return TRUE when the --not-a-term argument was found.
+ */
+    int
+is_not_a_term()
+{
+    return params.not_a_term;
+}
+
+/*
  * Main loop: Execute Normal mode commands until exiting Vim.
  * Also used to handle commands in the command-line window, until the window
  * is closed.
diff --git a/src/proto/main.pro b/src/proto/main.pro
index f8abb94..278d1ad 100644
--- a/src/proto/main.pro
+++ b/src/proto/main.pro
@@ -1,6 +1,7 @@
 /* main.c */
 int vim_main2(void);
 void common_init(mparm_T *paramp);
+int is_not_a_term(void);
 void main_loop(int cmdwin, int noexmode);
 void getout_preserve_modified(int exitval);
 void getout(int exitval);
diff --git a/src/term.c b/src/term.c
index 75c9fbf..cac47da 100644
--- a/src/term.c
+++ b/src/term.c
@@ -1705,7 +1705,8 @@
 		{
 		    screen_start();	/* don't know where cursor is now */
 		    out_flush();
-		    ui_delay(2000L, TRUE);
+		    if (!is_not_a_term())
+			ui_delay(2000L, TRUE);
 		}
 		set_string_option_direct((char_u *)"term", -1, term,
 								 OPT_FREE, 0);
diff --git a/src/testdir/test_startup.vim b/src/testdir/test_startup.vim
index 2185b4d..bce431f 100644
--- a/src/testdir/test_startup.vim
+++ b/src/testdir/test_startup.vim
@@ -216,7 +216,7 @@
   endif
 
   let save_term = $TERM
-  let $TERM = 'unknown'
+  let $TERM = 'unknownxxx'
   let out = system(GetVimCommand() . ' -c''set term'' -c cq')
   call assert_match("defaulting to 'ansi'", out)
   let $TERM = save_term
diff --git a/src/version.c b/src/version.c
index 8de7e66..3a6070b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    539,
+/**/
     538,
 /**/
     537,