[GSoC] extensions.partialClone and promisor remote fetch order

[Lorenzo Pegorari <lorenzo.pegorari2002@gmail.com>]

Hi everyone. In the past weeks I deeply studied the documentation
regarding the GSoC'26 idea "Implement promisor remote fetch ordering". I
am preparing a proposal that is as detailed as possible, and that tries
to answer to as many questions as possible. I am also experimenting a
lot with multiple promisor remotes configurations, and creating some
examples that I will showcase in my proposal.


I have a question regarding the interaction between the config
"extensions.partialClone" and a possible fetch ordering mechanism:
 * from my understanding, and from my personal tests, it looks like
   "extensions.partialClone" is not essential when working with multiple
   promisor remotes. Having these promisor remotes setted up with
   "remote.<name>.promisor" and "remote.<name>.partialCloneFilter" seems
   sufficient. In this case, the promisor remotes will be tried one
   after the other, in the order in which they appear in the config.
 * if "extensions.partialClone" is present, then the promisor remote
   configured using the "extensions.partialClone" config var will be the
   last one tried when fetching an object.

1. is what I explained correct?
2. when the fetch ordering mechanism will be added, this config var will
   not be useful anymore. How should it be handled? It probably can't
   just be removed, so the fetch ordering mechanism should be flexible
   enough to handle a situation where "extensions.partialClone" is
   present, correct?


Thanks,
Lorenzo