Fix symlink handling in OSFS

fs/base.py

@@ -22,6 +22,7 @@
 import six
 
 from . import copy, errors, fsencode, iotools, move, tools, walk, wildcard
+from .enums import ResourceType
 from .glob import BoundGlobber
 from .mode import validate_open_mode
 from .path import abspath, join, normpath
@@ -49,7 +50,6 @@
         Union,
     )
     from types import TracebackType
-    from .enums import ResourceType
     from .info import Info, RawInfo
     from .subfs import SubFS
     from .permissions import Permissions
@@ -981,8 +981,10 @@ def islink(self, path):
             bool: `True` if ``path`` maps to a symlink.
 
         """
-        self.getinfo(path)
-        return False
+        try:
+            return self.gettype(path) == ResourceType.symlink
+        except errors.ResourceNotFound:
+            return False
 
     def lock(self):
         # type: () -> RLock

fs/osfs.py

@@ -599,7 +599,7 @@ def gettype(self, path):
         self.check()
         sys_path = self._to_sys_path(path)
         with convert_os_errors("gettype", path):
-            stat = os.stat(sys_path)
+            stat = os.lstat(sys_path)
         resource_type = self._get_type_from_stat(stat)
         return resource_type
 
@@ -608,8 +608,6 @@ def islink(self, path):
         self.check()
         _path = self.validatepath(path)
         sys_path = self._to_sys_path(_path)
-        if not self.exists(path):
-            raise errors.ResourceNotFound(path)
         with convert_os_errors("islink", path):
             return os.path.islink(sys_path)
 

fs/test.py

@@ -392,8 +392,7 @@ def test_isdir(self):
     def test_islink(self):
         self.fs.touch("foo")
         self.assertFalse(self.fs.islink("foo"))
-        with self.assertRaises(errors.ResourceNotFound):
-            self.fs.islink("bar")
+        self.assertFalse(self.fs.islink("bar"))
 
     def test_getsize(self):
         self.fs.writebytes("empty", b"")

tests/test_osfs.py

@@ -11,6 +11,7 @@
 import pytest
 
 from fs import osfs, open_fs
+from fs.enums import ResourceType
 from fs.path import relpath, dirname
 from fs import errors
 from fs.test import FSTestCases
@@ -203,3 +204,19 @@ def test_complex_geturl(self):
 
     def test_geturl_return_no_url(self):
         self.assertRaises(errors.NoURL, self.fs.geturl, "test/path", "upload")
+
+    @pytest.mark.skipif(not hasattr(os, "symlink"), reason="No symlink support")
+    def test_symlinks_dangling(self):
+        self.fs.create("a")
+        os.symlink(self.fs.getsyspath("a"), self.fs.getsyspath("b"))
+
+        self.assertTrue(self.fs.exists("a"))
+        self.assertFalse(self.fs.islink("a"))
+        self.assertEqual(self.fs.gettype("a"), ResourceType.file)
+        self.assertTrue(self.fs.exists("b"))
+        self.assertTrue(self.fs.islink("b"))
+        self.assertEqual(self.fs.gettype("b"), ResourceType.symlink)
+
+        self.fs.remove("a")
+        self.assertTrue(self.fs.islink("b"))
+        self.assertEqual(self.fs.gettype("b"), ResourceType.symlink)