commit https://github.com/vim/vim/commit/2932359000b2f918d5fade79ea4d124d5943cd07 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Jul 24 22:04:11 2016 +0200 patch 7.4.2101 Problem: Looping over windows, buffers and tab pages is inconsistant. Solution: Use FOR_ALL_ macros everywhere. (Yegappan Lakshmanan)

--- a/src/edit.c
+++ b/src/edit.c
@@ -4239,7 +4239,7 @@ ins_compl_get_exp(pos_T *ini)
 
     if (!compl_started)
     {
-	for (ins_buf = firstbuf; ins_buf != NULL; ins_buf = ins_buf->b_next)
+	FOR_ALL_BUFFERS(ins_buf)
 	    ins_buf->b_scanned = 0;
 	found_all = FALSE;
 	ins_buf = curbuf;