Added handling for readlink for broken link with trailing separator

- see pytest-dev#396

pyfakefs/fake_filesystem.py

@@ -2567,11 +2567,17 @@ def readlink(self, path):
         if self.ends_with_path_separator(path):
             if not self.is_windows_fs and self.exists(path):
                 self.raise_os_error(errno.EINVAL, path)
-            if not self.is_macos and not self.exists(link_obj.path):
-                error = errno.EINVAL if self.is_windows_fs else errno.ELOOP
+            if not self.exists(link_obj.path):
+                if self.is_windows_fs:
+                    error = errno.EINVAL
+                elif link_obj.path == link_obj.contents:
+                    if self.is_macos:
+                        return
+                    error = errno.ELOOP
+                else:
+                    error = errno.ENOENT
                 self.raise_os_error(error, link_obj.path)
 
-
         return link_obj.contents
 
     def makedir(self, dir_name, mode=PERM_DEF):

pyfakefs/tests/fake_os_test.py

@@ -637,20 +637,23 @@ def test_broken_symlink_with_trailing_separator_windows(self):
         self.assert_raises_os_error(errno.EINVAL, self.os.symlink,
             link_path + self.os.sep, link_path + self.os.sep)
 
-    def test_circular_readlink_with_trailing_separator_372_linux(self):
+    def test_circular_readlink_with_trailing_separator_linux(self):
+        # Regression test for #372
         self.check_linux_only()
         file_path = self.make_path('foo')
         self.os.symlink(file_path, file_path)
         self.assert_raises_os_error(errno.ELOOP, self.os.readlink,
                                     file_path + self.os.sep)
 
-    def test_circular_readlink_with_trailing_separator_372_macos(self):
+    def test_circular_readlink_with_trailing_separator_macos(self):
+        # Regression test for #372
         self.check_macos_only()
         file_path = self.make_path('foo')
         self.os.symlink(file_path, file_path)
         print(self.os.readlink(file_path + self.os.sep))
 
-    def test_circular_readlink_with_trailing_separator_372_windows(self):
+    def test_circular_readlink_with_trailing_separator_windows(self):
+        # Regression test for #372
         self.check_windows_only()
         self.skip_if_symlink_not_supported()
         file_path = self.make_path('foo')
@@ -2219,6 +2222,16 @@ def test_rename_broken_link_with_trailing_sep_windows(self):
         self.assert_raises_os_error(
             errno.EINVAL, self.os.rename, link_path, self.make_path('target'))
 
+    def test_readlink_broken_link_with_trailing_sep_posix(self):
+        self.check_posix_only()
+        link_path = self.create_broken_link_path_with_trailing_sep()
+        self.assert_raises_os_error(errno.ENOENT, self.os.readlink, link_path)
+
+    def test_readlink_broken_link_with_trailing_sep_windows(self):
+        self.check_windows_only()
+        link_path = self.create_broken_link_path_with_trailing_sep()
+        self.assert_raises_os_error(errno.EINVAL, self.os.readlink, link_path)
+
     def test_islink_broken_link_with_trailing_sep(self):
         link_path = self.create_broken_link_path_with_trailing_sep()
         self.assertFalse(self.os.path.islink(link_path))