This is probably scope creep for this series, but do you guys think we should do the same for config variables completion? We currently maintain a giant list at the end of _git_config(). Extracting the list from Documentation/config.txt to keep it in a C array does not look super hard. There will be some special handling for advice.* or color.<slot>... but overall I still think it's a net gain.
Listing all recognizable config variables from "git config" (or "git help") would be lovely, but I don't think it helps unless we could print a short summary line each variable, but this info is not available anywhere. -- Duy
