Issue #24120: Ignore PermissionError in pathlib.Path.[r]glob(). Ulrich Petri.

Author: gvanrossum

Lib/pathlib.py

@@ -454,12 +454,15 @@ def __init__(self, name, child_parts):
         _Selector.__init__(self, child_parts)
 
     def _select_from(self, parent_path, is_dir, exists, listdir):
-        if not is_dir(parent_path):
+        try:
+            if not is_dir(parent_path):
+                return
+            path = parent_path._make_child_relpath(self.name)
+            if exists(path):
+                for p in self.successor._select_from(path, is_dir, exists, listdir):
+                    yield p
+        except PermissionError:
             return
-        path = parent_path._make_child_relpath(self.name)
-        if exists(path):
-            for p in self.successor._select_from(path, is_dir, exists, listdir):
-                yield p
 
 
 class _WildcardSelector(_Selector):
@@ -469,15 +472,19 @@ def __init__(self, pat, child_parts):
         _Selector.__init__(self, child_parts)
 
     def _select_from(self, parent_path, is_dir, exists, listdir):
-        if not is_dir(parent_path):
+        try:
+            if not is_dir(parent_path):
+                return
+            cf = parent_path._flavour.casefold
+            for name in listdir(parent_path):
+                casefolded = cf(name)
+                if self.pat.match(casefolded):
+                    path = parent_path._make_child_relpath(name)
+                    for p in self.successor._select_from(path, is_dir, exists, listdir):
+                        yield p
+        except PermissionError:
             return
-        cf = parent_path._flavour.casefold
-        for name in listdir(parent_path):
-            casefolded = cf(name)
-            if self.pat.match(casefolded):
-                path = parent_path._make_child_relpath(name)
-                for p in self.successor._select_from(path, is_dir, exists, listdir):
-                    yield p
+
 
 
 class _RecursiveWildcardSelector(_Selector):
@@ -494,19 +501,22 @@ def _iterate_directories(self, parent_path, is_dir, listdir):
                     yield p
 
     def _select_from(self, parent_path, is_dir, exists, listdir):
-        if not is_dir(parent_path):
+        try:
+            if not is_dir(parent_path):
+                return
+            with _cached(listdir) as listdir:
+                yielded = set()
+                try:
+                    successor_select = self.successor._select_from
+                    for starting_point in self._iterate_directories(parent_path, is_dir, listdir):
+                        for p in successor_select(starting_point, is_dir, exists, listdir):
+                            if p not in yielded:
+                                yield p
+                                yielded.add(p)
+                finally:
+                    yielded.clear()
+        except PermissionError:
             return
-        with _cached(listdir) as listdir:
-            yielded = set()
-            try:
-                successor_select = self.successor._select_from
-                for starting_point in self._iterate_directories(parent_path, is_dir, listdir):
-                    for p in successor_select(starting_point, is_dir, exists, listdir):
-                        if p not in yielded:
-                            yield p
-                            yielded.add(p)
-            finally:
-                yielded.clear()
 
 
 #

Lib/test/test_pathlib.py

@@ -1203,26 +1203,33 @@ class _BasePathTest(object):
 
     # (BASE)
     #  |
-    #  |-- dirA/
-    #       |-- linkC -> "../dirB"
-    #  |-- dirB/
-    #  |    |-- fileB
-    #       |-- linkD -> "../dirB"
-    #  |-- dirC/
-    #  |    |-- fileC
-    #  |    |-- fileD
+    #  |-- brokenLink -> non-existing
+    #  |-- dirA
+    #  |   `-- linkC -> ../dirB
+    #  |-- dirB
+    #  |   |-- fileB
+    #  |   `-- linkD -> ../dirB
+    #  |-- dirC
+    #  |   |-- dirD
+    #  |   |   `-- fileD
+    #  |   `-- fileC
+    #  |-- dirE
     #  |-- fileA
-    #  |-- linkA -> "fileA"
-    #  |-- linkB -> "dirB"
+    #  |-- linkA -> fileA
+    #  `-- linkB -> dirB
     #
 
     def setUp(self):
+        def cleanup():
+            os.chmod(join('dirE'), 0o777)
+            support.rmtree(BASE)
+        self.addCleanup(cleanup)
         os.mkdir(BASE)
-        self.addCleanup(support.rmtree, BASE)
         os.mkdir(join('dirA'))
         os.mkdir(join('dirB'))
         os.mkdir(join('dirC'))
         os.mkdir(join('dirC', 'dirD'))
+        os.mkdir(join('dirE'))
         with open(join('fileA'), 'wb') as f:
             f.write(b"this is file A\n")
         with open(join('dirB', 'fileB'), 'wb') as f:
@@ -1231,6 +1238,7 @@ def setUp(self):
             f.write(b"this is file C\n")
         with open(join('dirC', 'dirD', 'fileD'), 'wb') as f:
             f.write(b"this is file D\n")
+        os.chmod(join('dirE'), 0)
         if not symlink_skip_reason:
             # Relative symlinks
             os.symlink('fileA', join('linkA'))
@@ -1306,7 +1314,7 @@ def test_iterdir(self):
         p = P(BASE)
         it = p.iterdir()
         paths = set(it)
-        expected = ['dirA', 'dirB', 'dirC', 'fileA']
+        expected = ['dirA', 'dirB', 'dirC', 'dirE', 'fileA']
         if not symlink_skip_reason:
             expected += ['linkA', 'linkB', 'brokenLink']
         self.assertEqual(paths, { P(BASE, q) for q in expected })

Misc/ACKS

@@ -1075,6 +1075,7 @@ Gabriel de Perthuis
 Tim Peters
 Benjamin Peterson
 Joe Peterson
+Ulrich Petri
 Chris Petrilli
 Roumen Petrov
 Bjorn Pettersen

Misc/NEWS

@@ -13,6 +13,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #24120: Ignore PermissionError when traversing a tree with
+  pathlib.Path.[r]glob().  Patch by Ulrich Petri.
+
 
 What's New in Python 3.4.4?
 ===========================