Prevent aliases to be duplicated: no need to apply root aliases from
composer.json on packages currently locked, they should have their
aliases in the lock file, otherwise request an update.
This is necessary to allow the requiring of new packages which replace
packages currently locked without requiring explicitly listing them as
an argument, so simplifies the composer require command
This reduces code complexity while making partial updates more
predictable. This also allows composer require to successfully run a
partial update for a new package with transitive dependency updates.
additionally mark all packages replaced by fixed packages as loaded as
there is no need to load those names at all, since the fixed package
will provide them
The only type of request job remaining was "install" which is really a
root requirement. The only other kind of input for the solver is now a
set of fixed packages.
Rules have been updated to account for only two kinds of former job
reason: FIXED or ROOT_REQUIRE. The job property has always been
redundant and has been removed, since reasonData suffices.
Problem reasons are always rules, so the unnecessary wrapping in an
array has been removed.
We now only ever generate a single rule per root require or fixed
package, so there is no need for the solver to special handle disabling
"jobs" anymore, the rule can just be disabled as usual.
For consistency special handling of rules for jobs in problems has been
integrated into the rule class like all other rule reasons. As part of
this change the error message for root requirements has been improved a
bit to make it clearer where the package installation request came from.
The word job has also been removed from operations, which are called
operations, not jobs.
Yanick Witschi
Nils Adermann
Jordi Boggiano
Markus Staab