Consider all overwrites and not only the overwrites of one package wh…

…en building the marker intersection

src/poetry/puzzle/provider.py

@@ -638,8 +638,9 @@ def fmt_warning(d: Dependency) -> str:
                         dep_other.set_constraint(
                             dep_other.constraint.intersect(dep_any.constraint)
                         )
-            else:
-                # if there is no any marker dependency,
+            elif not inverted_marker.is_empty():
+                # if there is no any marker dependency
+                # and the inverted marker is not empty,
                 # a dependency with the inverted union of all markers is required
                 # in order to not miss other dependencies later, for instance:
                 #   - foo (1.0) ; python == 3.7
@@ -655,10 +656,11 @@ def fmt_warning(d: Dependency) -> str:
 
             overrides = []
             overrides_marker_intersection = AnyMarker()
-            for _dep in self._overrides.get(package, {}).values():
-                overrides_marker_intersection = overrides_marker_intersection.intersect(
-                    _dep.marker
-                )
+            for dep_overrides in self._overrides.values():
+                for _dep in dep_overrides.values():
+                    overrides_marker_intersection = (
+                        overrides_marker_intersection.intersect(_dep.marker)
+                    )
             for _dep in _deps:
                 if not overrides_marker_intersection.intersect(_dep.marker).is_empty():
                     current_overrides = self._overrides.copy()

tests/puzzle/test_solver.py

@@ -1414,6 +1414,49 @@ def test_solver_duplicate_dependencies_ignore_overrides_with_empty_marker_inters
     )
 
 
+def test_solver_duplicate_dependencies_ignore_overrides_with_empty_marker_intersection2(
+    solver: Solver, repo: Repository, package: Package
+):
+    """
+    Empty intersection between top level dependency and transient dependency.
+    """
+    package.add_dependency(Factory.create_dependency("A", {"version": "1.0"}))
+    package.add_dependency(
+        Factory.create_dependency("B", {"version": ">=2.0", "python": ">=3.7"})
+    )
+    package.add_dependency(
+        Factory.create_dependency("B", {"version": "*", "python": "<3.7"})
+    )
+
+    package_a10 = get_package("A", "1.0")
+    package_a10.add_dependency(
+        Factory.create_dependency("B", {"version": ">=2.0", "python": ">=3.7"})
+    )
+    package_a10.add_dependency(
+        Factory.create_dependency("B", {"version": "*", "python": "<3.7"})
+    )
+
+    package_b10 = get_package("B", "1.0")
+    package_b10.python_versions = "<3.7"
+    package_b20 = get_package("B", "2.0")
+    package_b20.python_versions = ">=3.7"
+
+    repo.add_package(package_a10)
+    repo.add_package(package_b10)
+    repo.add_package(package_b20)
+
+    transaction = solver.solve()
+
+    check_solver_result(
+        transaction,
+        [
+            {"job": "install", "package": package_b10},
+            {"job": "install", "package": package_b20},
+            {"job": "install", "package": package_a10},
+        ],
+    )
+
+
 def test_solver_duplicate_dependencies_sub_dependencies(
     solver: Solver, repo: Repository, package: ProjectPackage
 ):