patch 9.0.0339: no check if the return value of XChangeGC() is NULL Commit: https://github.com/vim/vim/commit/a63ad78ed31e36dbdf3a9cd28071dcdbefce7d19 Author: Bram Moolenaar <Bram@vim.org> Date: Wed Aug 31 12:01:54 2022 +0100 patch 9.0.0339: no check if the return value of XChangeGC() is NULL Problem: No check if the return value of XChangeGC() is NULL. Solution: Only use the return value when it is not NULL. (closes https://github.com/vim/vim/issues/11020)