updated for version 7.4.446
Problem:    In some situations, when setting up an environment to trigger an
            autocommand, the environment is not properly restored.
Solution:   Check the return value of switch_win() and call restore_win()
            always.  (Daniel Hahler)
diff --git a/src/misc2.c b/src/misc2.c
index 1f8878f..1fe0e87 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -1040,7 +1040,8 @@
     entered = TRUE;
 
 # ifdef FEAT_AUTOCMD
-    block_autocmds();	    /* don't want to trigger autocommands here */
+    /* Don't want to trigger autocommands from here on. */
+    block_autocmds();
 # endif
 
 # ifdef FEAT_WINDOWS