GitHub may not be the primary contributor to git, but they're certainly a significant user of it, and they _have_ contributed patches to upstream git. (example

GitHub may not be the primary contributor to git, but they're certainly a significant user of it, and they _have_ contributed patches to upstream git. (example, the '768 conflict' bug here: https://githubengineering.com/move-fast/ https://githubengineering.com/move-fast/)