commit https://github.com/vim/vim/commit/6650a694547eb744afa060ec62dd8270e99db9f2 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Jan 26 19:59:10 2016 +0100 patch 7.4.1181 Problem: free_tv() can't handle special variables. (Damien) Solution: Add the variable type.

--- a/src/eval.c
+++ b/src/eval.c
@@ -21608,6 +21608,7 @@ free_tv(varp)
 	    case VAR_FLOAT:
 #endif
 	    case VAR_UNKNOWN:
+	    case VAR_SPECIAL:
 		break;
 	    default:
 		EMSG2(_(e_intern2), "free_tv()");