patch 8.1.2406: leaking memory in test_paste and test_registers Commit: https://github.com/vim/vim/commit/6b649ac4fd0cbf88c5a05d82ad151d0ce980916a Author: Bram Moolenaar <Bram@vim.org> Date: Sat Dec 7 17:47:22 2019 +0100 patch 8.1.2406: leaking memory in test_paste and test_registers Problem: Leaking memory in test_paste and test_registers. Solution: Free the old title. Don't copy expr_line.

--- a/src/register.c
+++ b/src/register.c
@@ -2872,9 +2872,9 @@ write_reg_contents_ex(
 	p = vim_strnsave(str, (int)len);
 	if (p == NULL)
 	    return;
-	if (must_append)
+	if (must_append && expr_line != NULL)
 	{
-	    s = concat_str(get_expr_line_src(), p);
+	    s = concat_str(expr_line, p);
 	    vim_free(p);
 	    p = s;
 	}