Fix all failing tests

src/pip/_internal/commands/show.py

@@ -141,7 +141,7 @@ def print_results(distributions, list_files=False, verbose=False):
         canonical_name = canonicalize_name(name)
         required_by = [
             pkg.project_name for pkg in pkg_resources.working_set
-            if canonical_name in [required.name for required in pkg.requires()]
+            if canonical_name in [canonicalize_name(required.name) for required in pkg.requires()]
         ]
 
         write_output("Name: %s", name)

tests/data/src/required_by_capitalized/required_by_capitalized/__init__.py

@@ -0,0 +1 @@
+#

tests/data/src/required_by_capitalized/setup.py

@@ -0,0 +1,5 @@
+from setuptools import setup
+
+setup(name='Required_By_Capitalized',
+      version='1.0',
+      )

tests/data/src/required_by_mixed_capitalization/setup.py

@@ -1,6 +1,6 @@
 from setuptools import setup
 
-setup(name='requires_Capitalized',
-      version='0.1',
-      install_requires=['simple==1.0']
+setup(name='simple',
+      version='1.0',
+      install_requires=['required_by_Capitalized==1.0']
       )

tests/functional/test_show.py

@@ -205,7 +205,7 @@ def test_package_name_is_canonicalized(script, data):
     assert underscore_upper_show_result.stdout == dash_show_result.stdout
 
 
-def test_show_required_by_packages_simple(script, data):
+def test_show_required_by_packages_basic(script, data):
     """
     Test that installed packages that depend on this package are shown
     """
@@ -238,19 +238,23 @@ def test_show_required_by_packages_capitalized(script, data):
     assert 'Required-by: Requires-Capitalized' in lines
 
 
-def test_show_required_by_with_mixed_capitalization(script, data):
+def test_show_required_by_packages_requiring_capitalized(script, data):
     """
     Test that the installed packages which depend on a package are shown
     where the package has a name with a mix of
     lower and upper case letters
     """
+    required_package_path = os.path.join(data.src, 'required_by_capitalized')
+    script.pip(
+        'install', '--no-index', '-f', data.find_links, required_package_path
+    )
     editable_path = os.path.join(data.src, 'required_by_mixed_capitalization')
     script.pip(
         'install', '--no-index', '-f', data.find_links, editable_path
     )
 
-    result = script.pip('show', 'Requires_CapitalizeD')
+    result = script.pip('show', 'Required_By_Capitalized')
     lines = result.stdout.splitlines()
 
-    assert 'Name: Requires-Capitalized' in lines
+    assert 'Name: Required-By-Capitalized' in lines
     assert 'Required-by: simple' in lines