On Mon, Oct 18, 2021 at 01:48:03PM -0700, Jonathan Tan wrote: > > After some in-office discussion, here are the alternatives as I see it: > > (1) Introduce a "includeAfterIf" (or "deferIncludeIf", or some other > name) command that is executed after all config files are read. (If > there are multiple, they are executed in order of appearance.) > Files included by this mechanism cannot directly or indirectly > contain another "includeAfterIf". This is the same as what was > introduced in this patch set, except for the name of the directive. > > (2) Leave the name as "includeIf", and when it is encountered with a > remote-URL condition: continue parsing the config files, skipping > all "includeIf hasRemoteUrl", only looking for remote.*.url. After > that, resume the reading of config files at the first "includeIf > hasRemoteUrl", using the prior remote.*.url information gathered to > determine which files to include when "includeIf hasRemoteUrl" is > encountered. Files included by this mechanism cannot contain any > "remote.*.url" variables. > > In all cases, the include is executed if at least one remote URL > matches. > > There are other ideas including: > > (3) remote.*.url must appear before a "includeIf hasRemoteUrl" that > wants to match it. (But this doesn't fit our use case, in which a > repo config has the URL but a system or user config has the > include.) > > (4) "includeIf hasRemoteUrl" triggers a search of the repo config just > for remote.*.url. (I think this out-of-order config search is more > complicated than (2), though.) > > For (2), I think that prohibiting "remote.*.url" from any "includeIf > hasRemoteUrl" files sidesteps questions like "what happens when an > included file overrides the URL that made us include this file in the > first place" or "what happens if an included file includes a > remote.*.url that validates or invalidates a prior or subsequent file", > because now that cannot happen at all. My main concern with this > prohibition was that if we were to introduce another similar condition > (say, one based on remote names), what would happen? But I think this is > solvable - make the prohibitions based only on all the conditions that > the actually used, so if the user only uses conditions on remote URLs, > then the user can still set refspecs (for example), even after the > remote-name-condition feature is introduced in Git. > > For (1), it is simpler in concept (and also in implementation, I think). > The user just needs to know that certain includes are on-the-spot and > certain includes (the ones with "after" in the name) are deferred - in > particular, if a config variable isn't the value they expect, they'll > need to check that it wasn't introduced in an includeAfterIf file. (And > the user also needs to figure out that if they want to override such a > variable, they'll need to make their own includeAfterIf with an > always-true condition.) > > From the prior replies, I think that people will be more interested in > (2) as it preserves the "last config wins" rule, and I'm inclined to go > for (2) too. I'll see if others have any other opinions, and if not I'll > see how the implementation of (2) will look like. Another concern which came up for me in a private conversation today - How difficult will it be for users to override this include directive if it is set somewhere outside of their control? For example: /etc/gitconfig: [includeIf hasRemoteUrl.https://example.com/example.git] // or whatever path = /etc/some-special-config Will it be possible for a user to "un-include" /etc/some-special-config themselves? I don't think this should change your patch much - if my understanding is correct, we also don't have a way to "un-include" existing include or includeIf directives made outside of the user's control. But I wonder if it'd be useful to think about some way to do that. Maybe we can teach the config parse how to include a config file in reverse? Maybe we need a "neverInclude" directive? Food for thought, anyway. Sorry, but I won't have time to take a look at the rest of this series til next week. - Emily
