On Wed, Apr 13, 2022 at 10:41 PM Andrew Oakley <andrew@xxxxxxxxxxxxx> wrote: > > On Wed, 13 Apr 2022 06:24:29 +0000 > "Tao Klerks via GitGitGadget" <gitgitgadget@xxxxxxxxx> wrote: > > Make the changelist-description- and user-fullname-handling code > > python-runtime-agnostic, introducing three "strategies" selectable via > > config: > > - 'legacy', behaving as previously under python2, > > - 'strict', behaving as previously under python3, and > > - 'fallback', favoring utf-8 but supporting a secondary encoding when > > utf-8 decoding fails, and finally replacing remaining unmappable > > bytes. > > I was thinking about making the config option be a list of encodings to > try. So the options you've given map something like this: > - "legacy" -> "raw" > - "strict" -> "utf8" > - "fallback" -> "utf8 cp1252" (or whatever is configured) > > This doesn't handle the case of using a replacement character, but in > reality I suspect that fallback encoding will always be a legacy 8bit > codec anyway. > > I think what you've proposed is fine too, I'm not sure what would end > up being easier to understand. I'm not sure I understand the proposal... Specifically, I don't understand how "raw" would work in that scheme. In "my" current scheme, there is a big difference between "legacy" and the other two strategies: the legacy strategy reads "raw", but also *writes* "raw". The other schemes read whatever encoding, and then write utf-8. In the case of strict, that actually works out the same as "raw", as long as the input bytes were valid utf-8 (and otherwise nothing happens anyway). In the case of fallback, that's a completely different behavior to legacy's read-raw write-raw. Is your proposal to independently specify the read encodings *and* the write encoding, as separate parameters? That was actually my original approach, but it turned out to, in my opinion, be harder to understand (and implement :) ) > > > * Does it make sense to make "fallback" the default decoding > > strategy in python3? This is definitely a change in behavior, but I > > believe for the better; failing with "we defaulted to strict, but you > > can run again with this other option if you want it to work" seems > > unkind, only making sense if we thought fallback to cp1252 would be > > wrong in a substantial proportion of cases... > > The only issue I can see with changing the default is that it might > lead to a surprising loss of data for someone migrating to git. Maybe > print a warning the first time git-p4 encounters something that can't be > decoded as UTF-8, but then continue with the fallback to cp1252? Honestly, I'm not sure how much a warning does. In my perforce repo, for example, any new warnings during the import would get drowned out by the mac metadata ignoring warnings. I understand and share the data loss concern. As I just answered Ævar, I *think* I'd like to address the data loss concern by escaping all x80+ bytes if something cannot be interpreted even using the fallback encoding. In a commit message there could also be a suffix explaining what happened, although I suspect that's pointless complexity. The advantage of this approach is that it makes it *possible* to reconstruct the original bytestream precisely, but without creating badly-encoded git commit messages that need to be skirted around. > > > * Is it OK to duplicate the bulk of the testing code across > > t9835-git-p4-metadata-encoding-python2.sh and > > t9836-git-p4-metadata-encoding-python3.sh? > > * Is it OK to explicitly call "git-p4.py" in tests, rather than > > the build output "git-p4", in order to be able to select the python > > runtime on a per-test basis? Is there a better approach? > > I tried to find a nicer way to do this and failed. OK thx. > > > * Is the naming of the strategies appropriate? Should the default > > python2 strategy be called something less opinionated, like > > "passthrough"? > > I think that "passthrough" or "raw" would be more descriptive names. > OK thx, I'll take "passthrough" as it feels slightly less positive than "raw", for some reason that I can't put my finger on :) > The changes to git-p4 itself look good to me. I think that dealing > with bytes more and strings less will be good going forward. Thx for your feedback!
