patch 8.2.4642: Vim9: in :def function script var cannot be null Commit: https://github.com/vim/vim/commit/859cc21c6b60af07b549456b7d050a03b3e48bc9 Author: Bram Moolenaar <Bram@vim.org> Date: Mon Mar 28 15:22:35 2022 +0100 patch 8.2.4642: Vim9: in :def function script var cannot be null Problem: Vim9: in :def function script var cannot be null. Solution: Only initialize a script variable when not set to a null value. (closes #10034)