Worked on the vim/vim repository to improve core editor correctness and user experience by addressing a bug in the Progress syntax file. Focused on ensuring that per-buffer expandtab preferences were respected by replacing the global set command with setlocal in Vim script, which prevented unintended indentation changes in newly opened buffers. This change resolved issue #19458 and enhanced consistency for users with personalized editor configurations. Demonstrated expertise in Vim scripting, editor configuration, and syntax highlighting while managing the full lifecycle of the fix, from analysis and patching to collaborative review and commit, ensuring robust code hygiene and maintainability.