updated for version 7.2.331
Problem:    Can't interrupt "echo list" for a very long list.
Solution:   Call line_breakcheck() in list_join().
diff --git a/src/eval.c b/src/eval.c
index c076560..082324d 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -6475,6 +6475,7 @@
 	vim_free(tofree);
 	if (s == NULL)
 	    return FAIL;
+	line_breakcheck();
     }
     return OK;
 }