provider: do not merge deps from different sources

This change ensures that the provider is less eager when merging
duplicate dependencies for a package. In particular, takes into
consideration source type, url and reference if available.

src/poetry/puzzle/provider.py

@@ -550,19 +550,33 @@ class Provider:
         # An example of this is:
         #   - pypiwin32 (220); sys_platform == "win32" and python_version >= "3.6"
         #   - pypiwin32 (219); sys_platform == "win32" and python_version < "3.6"
-        duplicates: dict[str, list[Dependency]] = {}
+        #
+        # Additional care has to be taken to ensure that hidden constraints like that
+        # of source type, reference etc. are taking into consideration when duplicates
+        # are identified.
+        duplicates: dict[
+            tuple[str, str | None, str | None, str | None], list[Dependency]
+        ] = {}
         for dep in dependencies:
-            if dep.complete_name not in duplicates:
-                duplicates[dep.complete_name] = []
-
-            duplicates[dep.complete_name].append(dep)
+            key = (
+                dep.complete_name,
+                dep.source_type,
+                dep.source_url,
+                dep.source_reference,
+            )
+            if key not in duplicates:
+                duplicates[key] = []
+            duplicates[key].append(dep)
 
         dependencies = []
-        for dep_name, deps in duplicates.items():
+        for key, deps in duplicates.items():
             if len(deps) == 1:
                 dependencies.append(deps[0])
                 continue
 
+            extra_keys = ", ".join(k for k in key[1:] if k is not None)
+            dep_name = f"{key[0]} ({extra_keys})" if extra_keys else key[0]
+
             self.debug(f"<debug>Duplicate dependencies for {dep_name}</debug>")
 
             deps = self._merge_dependencies_by_marker(deps)

tests/puzzle/test_solver.py

@@ -14,6 +14,7 @@ from poetry.core.packages.vcs_dependency import VCSDependency
 from poetry.core.version.markers import parse_marker
 
 from poetry.factory import Factory
+from poetry.packages import DependencyPackage
 from poetry.puzzle import Solver
 from poetry.puzzle.exceptions import SolverProblemError
 from poetry.puzzle.provider import Provider as BaseProvider
@@ -1337,6 +1338,67 @@ def test_solver_duplicate_dependencies_different_constraints_merge_by_marker(
     )
 
 
+def test_solver_duplicate_dependencies_different_sources_types_are_preserved(
+    solver: Solver, repo: Repository, package: Package
+):
+    pendulum = get_package("pendulum", "2.0.3")
+    repo.add_package(pendulum)
+    repo.add_package(get_package("cleo", "1.0.0"))
+    repo.add_package(get_package("demo", "0.1.0"))
+
+    dependency_pypi = Factory.create_dependency("demo", ">=0.1.0")
+    dependency_git = Factory.create_dependency(
+        "demo", {"git": "https://github.com/demo/demo.git"}, groups=["dev"]
+    )
+    package.add_dependency(dependency_git)
+    package.add_dependency(dependency_pypi)
+
+    demo = Package(
+        "demo",
+        "0.1.2",
+        source_type="git",
+        source_url="https://github.com/demo/demo.git",
+        source_reference=DEFAULT_SOURCE_REF,
+        source_resolved_reference="9cf87a285a2d3fbb0b9fa621997b3acc3631ed24",
+    )
+
+    transaction = solver.solve()
+
+    ops = check_solver_result(
+        transaction,
+        [{"job": "install", "package": pendulum}, {"job": "install", "package": demo}],
+    )
+
+    op = ops[1]
+
+    assert op.package.source_type == demo.source_type
+    assert op.package.source_reference == DEFAULT_SOURCE_REF
+    assert op.package.source_resolved_reference.startswith(
+        demo.source_resolved_reference
+    )
+
+    complete_package = solver.provider.complete_package(
+        DependencyPackage(package.to_dependency(), package)
+    )
+
+    assert len(complete_package.all_requires) == 2
+
+    pypi, git = complete_package.all_requires
+
+    assert isinstance(pypi, Dependency)
+    assert pypi == dependency_pypi
+
+    assert isinstance(git, VCSDependency)
+    assert git.constraint
+    assert git.constraint != dependency_git.constraint
+    assert (git.name, git.source_type, git.source_url, git.source_reference) == (
+        dependency_git.name,
+        dependency_git.source_type,
+        dependency_git.source_url,
+        DEFAULT_SOURCE_REF,
+    )
+
+
 def test_solver_duplicate_dependencies_different_constraints_merge_no_markers(
     solver: Solver, repo: Repository, package: Package
 ):