patch 7.4.1961
Problem:    When 'insertmode' is reset while doing completion the popup menu
            remains even though Vim is in Normal mode.
Solution:   Ignore stop_insert_mode when the popup menu is visible.  Don't set
            stop_insert_mode when 'insertmode' was already off. (Christian
            Brabandt)
diff --git a/src/edit.c b/src/edit.c
index 0ba2627..234e03d 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -649,7 +649,11 @@
 	if (update_Insstart_orig)
 	    Insstart_orig = Insstart;
 
-	if (stop_insert_mode)
+	if (stop_insert_mode
+#ifdef FEAT_INS_EXPAND
+		&& !pum_visible()
+#endif
+		)
 	{
 	    /* ":stopinsert" used or 'insertmode' reset */
 	    count = 0;