On Thu, Jun 6, 2013 at 12:09 AM, Junio C Hamano <gits...@pobox.com> wrote: > Duy Nguyen <pclo...@gmail.com> writes: > >> On Wed, Jun 5, 2013 at 4:12 AM, Eric Sunshine <sunsh...@sunshineco.com> >> wrote: >>>> +Caveats: >>>> + >>>> +1. Many of the placeholders in "PRETTY FORMATS" are designed to work >>>> + specifically on commit objects: when non-commit objects are >>>> + supplied, those placeholders won't work. >>> >>> Should "won't work" be expanded upon? It's not clear if this means >>> that git will outright crash, or if it will abort with an appropriate >>> error message, or if the directive will be displayed as-is or removed >>> from the output. >> >> It will be displayed as-is but that's a bit inconsistent: %(unknown) >> prints error and aborts while %unknown simply produces %unknown. The >> latter is how "git log --format" does it. But I think we could make >> for-each-ref --pretty to do the former for %unknown. It'll be >> consistent with %(unknown) and we do not need to elaborate much (it's >> pretty obvious when it does not work). > > The Caveat Eric is asking about talks about "what happens to a > %(field) that only makes sense for a commit when showing a ref > pointing at a non-commit?", but you are answering "what happend to a > %(invalidfield) that is not defined", aren't you?
Because %(field) is treated like %(invalidfield) in this case. I'm not saying this is the best thing to do though. > IIRC, the reason we show literal from "log --format" is to make it > easier for the person who misspelt %placeholder to spot it in the > output, and also make it easier for the person who use %placeholder > meant for newer versions of Git with an older one. It would be a > bit unnice to die for the latter, especially if the format string is > in a script or something. That makes more sense for for-each-ref than log because for-each-ref is a plumbing and should support scripting. But old for-each-ref will happily reject %(newplacholder) right away. Should we take this opportunity to change this behavior in for-each-ref too? > To "log --format", all input objects are expected to be commits, so > it does not have the "what does %(authordate) give when given a blob" > issue. > > But for "for-each-ref --format", it is perfectly normal that you may > feed a non-commit; it makes the mechanism unusable if you errored > out %(authordate) when showing a ref that points at a tag, doesn't > it? Substituting an inapplicable placeholder with an empty string > would be an easies way out, unless it learns a flexible/elaborate > conditional formatting mechanism, I would think. There is a blurred line here. %H (or %h) should produce an object name even for tags or blobs, but right now it produces "%H" instead. The same applies for %ad and friends, but these are clearly for commits and should probably behave like %(authordate), i.e. producing empty string. -- Duy -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
