fix: PEP 440 pre-release handling (part 2)

Remove implicit "allow-prereleases" in repository, consider explicit allow-prereleases in show, make search_for test in provider forward-compatible.

src/poetry/console/commands/show.py

@@ -522,18 +522,25 @@ lists all packages available."""
         from poetry.version.version_selector import VersionSelector
 
         # find the latest version allowed in this pool
+        requires = root.all_requires
         if package.is_direct_origin():
-            requires = root.all_requires
-
             for dep in requires:
                 if dep.name == package.name and dep.source_type == package.source_type:
                     provider = Provider(root, self.poetry.pool, NullIO())
                     return provider.search_for_direct_origin_dependency(dep)
 
+        allow_prereleases = False
+        for dep in requires:
+            if dep.name == package.name:
+                allow_prereleases = dep.allows_prereleases()
+                break
+
         name = package.name
         selector = VersionSelector(self.poetry.pool)
 
-        return selector.find_best_candidate(name, f">={package.pretty_version}")
+        return selector.find_best_candidate(
+            name, f">={package.pretty_version}", allow_prereleases
+        )
 
     def get_update_status(self, latest: Package, package: Package) -> str:
         from poetry.core.constraints.version import parse_constraint

src/poetry/repositories/repository.py

@@ -6,7 +6,6 @@ from typing import TYPE_CHECKING
 
 from packaging.utils import canonicalize_name
 from poetry.core.constraints.version import Version
-from poetry.core.constraints.version import VersionRange
 
 from poetry.repositories.abstract_repository import AbstractRepository
 from poetry.repositories.exceptions import PackageNotFound
@@ -34,11 +33,10 @@ class Repository(AbstractRepository):
 
     def find_packages(self, dependency: Dependency) -> list[Package]:
         packages = []
-        constraint, allow_prereleases = self._get_constraints_from_dependency(
-            dependency
-        )
         ignored_pre_release_packages = []
 
+        constraint = dependency.constraint
+        allow_prereleases = dependency.allows_prereleases()
         for package in self._find_packages(dependency.name, constraint):
             if package.yanked and not isinstance(constraint, Version):
                 # PEP 592: yanked files are always ignored, unless they are the only
@@ -92,23 +90,6 @@ class Repository(AbstractRepository):
 
         return results
 
-    @staticmethod
-    def _get_constraints_from_dependency(
-        dependency: Dependency,
-    ) -> tuple[VersionConstraint, bool]:
-        constraint = dependency.constraint
-
-        allow_prereleases = dependency.allows_prereleases()
-        if isinstance(constraint, VersionRange) and (
-            constraint.max is not None
-            and constraint.max.is_unstable()
-            or constraint.min is not None
-            and constraint.min.is_unstable()
-        ):
-            allow_prereleases = True
-
-        return constraint, allow_prereleases
-
     def _find_packages(
         self, name: NormalizedName, constraint: VersionConstraint
     ) -> list[Package]:

tests/puzzle/test_provider.py

@@ -67,15 +67,7 @@ def provider(root: ProjectPackage, pool: RepositoryPool) -> Provider:
         (Dependency("foo", "<2"), [Package("foo", "1")]),
         (Dependency("foo", "<2", extras=["bar"]), [Package("foo", "1")]),
         (Dependency("foo", ">=1"), [Package("foo", "2"), Package("foo", "1")]),
-        (
-            Dependency("foo", ">=1a"),
-            [
-                Package("foo", "3a"),
-                Package("foo", "2"),
-                Package("foo", "2a"),
-                Package("foo", "1"),
-            ],
-        ),
+        (Dependency("foo", ">=1a"), [Package("foo", "2"), Package("foo", "1")]),
         (
             Dependency("foo", ">=1", allows_prereleases=True),
             [
@@ -101,6 +93,17 @@ def test_search_for(
     repository.add_package(foo2a)
     repository.add_package(foo2)
     repository.add_package(foo3a)
+    # TODO: remove workaround when poetry-core with
+    #       https://github.com/python-poetry/poetry-core/pull/543 is available
+    if str(dependency.constraint) == ">=1a":
+        result = provider.search_for(dependency)
+        assert result == expected or result == [
+            Package("foo", "3a"),
+            Package("foo", "2"),
+            Package("foo", "2a"),
+            Package("foo", "1"),
+        ]
+        return
     assert provider.search_for(dependency) == expected