Add test for multiple .dist-info in wheel

tests/functional/test_install_wheel.py

@@ -4,6 +4,7 @@ import os
 
 import pytest
 
+from tests.lib import create_basic_wheel_for_package
 from tests.lib.path import Path
 
 
@@ -432,3 +433,21 @@ def test_wheel_install_with_no_cache_dir(script, tmpdir, data):
     package = data.packages.joinpath("simple.dist-0.1-py2.py3-none-any.whl")
     result = script.pip('install', '--no-cache-dir', '--no-index', package)
     result.assert_installed('simpledist', editable=False)
+
+
+def test_wheel_install_fails_with_extra_dist_info(script):
+    package = create_basic_wheel_for_package(
+        script,
+        "simple",
+        "0.1.0",
+        extra_files={
+            "unrelated-2.0.0.dist-info/WHEEL": "Wheel-Version: 1.0",
+            "unrelated-2.0.0.dist-info/METADATA": (
+                "Name: unrelated\nVersion: 2.0.0\n"
+            ),
+        },
+    )
+    result = script.pip(
+        "install", "--no-cache-dir", "--no-index", package, expect_error=True
+    )
+    assert "Multiple .dist-info directories" in result.stderr

tests/lib/__init__.py

@@ -921,8 +921,9 @@ def create_test_package_with_setup(script, **setup_kwargs):
     return pkg_path
 
 
-def create_basic_wheel_for_package(script, name, version,
-                                   depends=None, extras=None):
+def create_basic_wheel_for_package(
+    script, name, version, depends=None, extras=None, extra_files=None
+):
     if depends is None:
         depends = []
     if extras is None:
@@ -966,6 +967,9 @@ def create_basic_wheel_for_package(script, name, version,
         "{dist_info}/RECORD": ""
     }
 
+    if extra_files:
+        files.update(extra_files)
+
     # Some useful shorthands
     archive_name = "{name}-{version}-py2.py3-none-any.whl".format(
         name=name, version=version