runfiles: rlocation() checks if arg is normalized

rlocation() now validates that the path argument
is normalized, i.e. contains none of:
- current directory references (".")
- uplevel references ("..")
- double slash ("//")

This helps avoiding a bug similar to https://github.com/bazelbuild/bazel/pull/5083.

See https://github.com/bazelbuild/bazel/pull/4460

Change-Id: Ia73fa2df1eae86fc7084162c24e144129672742d

Closes #5085.

Change-Id: Ia73fa2df1eae86fc7084162c24e144129672742d
PiperOrigin-RevId: 194074072

2 files changed, 21 insertions, 5 deletions

diff --git a/tools/python/runfiles/runfiles.py b/tools/python/runfiles/runfiles.py
index 17e4121a0f..1053319eca 100644
--- a/tools/python/runfiles/runfiles.py
+++ b/tools/python/runfiles/runfiles.py
@@ -119,15 +119,15 @@ class _Runfiles(object):
       None if the method doesn't know about this runfile
     Raises:
       TypeError: if `path` is not a string
-      ValueError: if `path` is None or empty, or it's absolute or contains
-        uplevel references
+      ValueError: if `path` is None or empty, or it's absolute or not normalized
     """
     if not path:
       raise ValueError()
     if not isinstance(path, str):
       raise TypeError()
-    if ".." in path:
-      raise ValueError("path contains uplevel references: \"%s\"" % path)
+    if (path.startswith("../") or "/.." in path or path.startswith("./") or
+        "/./" in path or path.endswith("/.") or "//" in path):
+      raise ValueError("path is not normalized: \"%s\"" % path)
     if path[0] == "\\":
       raise ValueError("path is absolute without a drive letter: \"%s\"" % path)
     if os.path.isabs(path):
diff --git a/tools/python/runfiles/runfiles_test.py b/tools/python/runfiles/runfiles_test.py
index bbe1c84be4..f8373054c8 100644
--- a/tools/python/runfiles/runfiles_test.py
+++ b/tools/python/runfiles/runfiles_test.py
@@ -28,8 +28,24 @@ class RunfilesTest(unittest.TestCase):
     self.assertRaises(ValueError, lambda: r.Rlocation(None))
     self.assertRaises(ValueError, lambda: r.Rlocation(""))
     self.assertRaises(TypeError, lambda: r.Rlocation(1))
-    self.assertRaisesRegexp(ValueError, "contains uplevel",
+    self.assertRaisesRegexp(ValueError, "is not normalized",
+                            lambda: r.Rlocation("../foo"))
+    self.assertRaisesRegexp(ValueError, "is not normalized",
                             lambda: r.Rlocation("foo/.."))
+    self.assertRaisesRegexp(ValueError, "is not normalized",
+                            lambda: r.Rlocation("foo/../bar"))
+    self.assertRaisesRegexp(ValueError, "is not normalized",
+                            lambda: r.Rlocation("./foo"))
+    self.assertRaisesRegexp(ValueError, "is not normalized",
+                            lambda: r.Rlocation("foo/."))
+    self.assertRaisesRegexp(ValueError, "is not normalized",
+                            lambda: r.Rlocation("foo/./bar"))
+    self.assertRaisesRegexp(ValueError, "is not normalized",
+                            lambda: r.Rlocation("//foobar"))
+    self.assertRaisesRegexp(ValueError, "is not normalized",
+                            lambda: r.Rlocation("foo//"))
+    self.assertRaisesRegexp(ValueError, "is not normalized",
+                            lambda: r.Rlocation("foo//bar"))
     self.assertRaisesRegexp(ValueError, "is absolute without a drive letter",
                             lambda: r.Rlocation("\\foo"))