_casbaseddirectory.py: Validate path components

This catches incorrect use of the `Directory` API.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/buildstream/storage/_casbaseddirectory.py b/src/buildstream/storage/_casbaseddirectory.py
index 0a5a557b4..484dc0789 100644
--- a/src/buildstream/storage/_casbaseddirectory.py
+++ b/src/buildstream/storage/_casbaseddirectory.py
@@ -329,6 +329,8 @@ class CasBasedDirectory(Directory):
             if not path:
                 continue
 
+            self.__validate_path_component(path)
+
             entry = current_dir.index.get(path)
 
             if entry:
@@ -726,6 +728,7 @@ class CasBasedDirectory(Directory):
     @contextmanager
     def open_file(self, *path: str, mode: str = "r"):
         subdir = self.descend(*path[:-1])
+        self.__validate_path_component(path[-1])
         entry = subdir.index.get(path[-1])
 
         if entry and entry.type != _FileType.REGULAR_FILE:
@@ -825,6 +828,7 @@ class CasBasedDirectory(Directory):
     def exists(self, *path, follow_symlinks=False):
         try:
             subdir = self.descend(*path[:-1], follow_symlinks=follow_symlinks)
+            self.__validate_path_component(path[-1])
             target = subdir.index.get(path[-1])
             if target is not None:
                 if follow_symlinks and target.type == _FileType.SYMLINK:
@@ -864,3 +868,7 @@ class CasBasedDirectory(Directory):
                 subdir.__add_files_to_result(path_prefix=relative_pathname, result=result)
             else:
                 result.files_written.append(relative_pathname)
+
+    def __validate_path_component(self, path):
+        if "/" in path:
+            raise VirtualDirectoryError("Invalid path component: '{}'".format(path))