Fix issue where file is detected as library code when it shouldn't. Fixes #457

src/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_filtering.py

@@ -11,6 +11,7 @@ from _pydev_imps._pydev_saved_modules import threading
 from pydevd_file_utils import normcase
 from _pydevd_bundle.pydevd_constants import USER_CODE_BASENAMES_STARTING_WITH, \
     LIBRARY_CODE_BASENAMES_STARTING_WITH, IS_PYPY
+from _pydevd_bundle import pydevd_constants
 
 try:
     xrange  # noqa
@@ -209,7 +210,11 @@ class FilesFiltering(object):
         roots = _convert_to_str_and_clear_empty(roots)
         new_roots = []
         for root in roots:
-            new_roots.append(self._absolute_normalized_path(root))
+            path = self._absolute_normalized_path(root)
+            if pydevd_constants.IS_WINDOWS:
+                new_roots.append(path + '\\')
+            else:
+                new_roots.append(path + '/')
         return new_roots
 
     def _absolute_normalized_path(self, filename):

src/debugpy/_vendored/pydevd/tests_python/test_pydevd_filtering.py

@@ -1,6 +1,36 @@
 from _pydevd_bundle.pydevd_constants import IS_WINDOWS
 
 
+def test_in_project_roots_prefix_01(tmpdir):
+    from _pydevd_bundle.pydevd_filtering import FilesFiltering
+    files_filtering = FilesFiltering()
+
+    another = str(tmpdir.join('another'))
+    assert not another.endswith('/') and not another.endswith('\\')
+
+    files_filtering.set_library_roots([another])
+    files_filtering.set_project_roots([])
+    assert not files_filtering.in_project_roots(another + '/f.py')
+    assert not files_filtering.in_project_roots(another + '\\f.py')
+
+    assert files_filtering.in_project_roots(another + 'f.py')
+
+
+def test_in_project_roots_prefix_02(tmpdir):
+    from _pydevd_bundle.pydevd_filtering import FilesFiltering
+    files_filtering = FilesFiltering()
+
+    another = str(tmpdir.join('another'))
+    assert not another.endswith('/') and not another.endswith('\\')
+
+    files_filtering.set_library_roots([])
+    files_filtering.set_project_roots([another])
+    assert files_filtering.in_project_roots(another + '/f.py')
+    assert files_filtering.in_project_roots(another + '\\f.py')
+
+    assert not files_filtering.in_project_roots(another + 'f.py')
+
+
 def test_in_project_roots(tmpdir):
     from _pydevd_bundle.pydevd_filtering import FilesFiltering
     files_filtering = FilesFiltering()