patch 8.0.1485: weird autocmd may cause arglist to be changed recursively

Problem:    Weird autocmd may cause arglist to be changed recursively.
Solution:   Prevent recursively changing the argument list. (Christian
            Brabandt, closes #2472)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index cd915c9..591775f 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -8058,6 +8058,16 @@
     int		fnum_len)
 {
     int		i;
+    static int  recursive = 0;
+
+    if (recursive)
+    {
+#ifdef FEAT_AUTOCMD
+	EMSG(_(e_au_recursive));
+#endif
+	return;
+    }
+    ++recursive;
 
     alist_clear(al);
     if (ga_grow(&al->al_ga, count) == OK)
@@ -8087,6 +8097,8 @@
 	FreeWild(count, files);
     if (al == &global_alist)
 	arg_had_last = FALSE;
+
+    --recursive;
 }
 
 /*
diff --git a/src/globals.h b/src/globals.h
index 737812c..943bb31 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1594,6 +1594,9 @@
 EXTERN char_u e_invalidreg[]    INIT(= N_("E850: Invalid register name"));
 #endif
 EXTERN char_u e_dirnotf[]	INIT(= N_("E919: Directory not found in '%s': \"%s\""));
+#ifdef FEAT_AUTOCMD
+EXTERN char_u e_au_recursive[]	INIT(= N_("E952: Autocommand caused recursive behavior"));
+#endif
 
 #ifdef FEAT_GUI_MAC
 EXTERN short disallow_gui	INIT(= FALSE);
diff --git a/src/version.c b/src/version.c
index f56ef35..963f611 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1485,
+/**/
     1484,
 /**/
     1483,