dirstate: block addition of paths containing "." and ".."

Summary:
Mergedrivers can call dirstate.add directly and are adding paths with
"." and "..". Let's block those paths.

Reviewed By: quark-zju

Differential Revision: D23375469

fbshipit-source-id: 64e9f20169cfd50325ecd8ebcc1dd3be7a5cb202

eden/scm/edenscm/mercurial/dirstate.py

@@ -577,6 +577,10 @@ class dirstate(object):
                 raise error.Abort(
                     _("cannot add non-root-relative path to dirstate: %s") % f
                 )
+            relativedirs = [".", ".."]
+            if any(s for s in f.split("/") if s in relativedirs):
+                raise error.Abort(_("cannot add path with relative parents: %s") % f)
+
             # shadows
             for d in util.finddirs(f):
                 if self._map.hastrackeddir(d):

eden/scm/lib/treestate/Cargo.toml

@@ -9,6 +9,7 @@ anyhow = "1.0.20"
 bitflags = "1.0.4"
 byteorder = "1.2.7"
 thiserror = "1.0.5"
+types = { path = "../types" }
 twox-hash = "*"
 vlqencoding = { version = "0.1.0", path = "../vlqencoding" }
 

eden/scm/lib/treestate/src/tree.rs

@@ -17,6 +17,8 @@ use std::cell::Cell;
 use std::collections::Bound;
 use std::io::{Cursor, Read, Write};
 
+use types::RepoPath;
+
 /// A node entry is an entry in a directory, either a file or another directory.
 #[derive(Debug)]
 pub(crate) enum NodeEntry<T> {
@@ -609,6 +611,8 @@ where
     /// Add a file to the node.  The name may contain a path, in which case sufficient
     /// subdirectories are updated to add or update the file.
     fn add(&mut self, store: &dyn StoreView, name: KeyRef, info: &T) -> Result<bool> {
+        // Construct a RepoPath so we match the core path validation logic.
+        let _ = RepoPath::from_utf8(name)?;
         let (new_entry, file_added) = match self.path_recurse(store, name)? {
             PathRecurse::Directory(_dir, path, node) => {
                 // The file is in a subdirectory.  Add it to the subdirectory.

eden/scm/lib/treestate/src/treestate.rs

@@ -210,9 +210,8 @@ mod tests {
     }
 
     // Some random paths extracted from fb-hgext, plus some manually added entries, shuffled.
-    const SAMPLE_PATHS: [&[u8]; 22] = [
+    const SAMPLE_PATHS: [&[u8]; 21] = [
         b".fbarcanist",
-        b"build/.",
         b"phabricator/phabricator_graphql_client_urllib.pyc",
         b"hgext3rd/__init__.py",
         b"hgext3rd/.git/objects/14/8f179e7e702ddedb54c53f2726e7f81b14a33f",
@@ -303,8 +302,8 @@ mod tests {
         let dir = TempDir::new("treestate").expect("tempdir");
         let mut state = new_treestate(dir.path().join("1"));
         assert!(state.has_dir(b"/").unwrap());
-        assert!(state.has_dir(b"build/").unwrap());
-        assert!(!state.has_dir(b"build2/").unwrap());
+        assert!(state.has_dir(b"hgext3rd/").unwrap());
+        assert!(!state.has_dir(b"hgext4th/").unwrap());
         assert!(state.has_dir(b"rust/radixbuf/.git/objects/").unwrap());
         assert!(!state.has_dir(b"rust/radixbuf/.git2/objects/").unwrap());
     }

eden/scm/tests/test-dirstate.t

@@ -93,3 +93,17 @@ Verify that status reports deleted files correctly
   $ hg status
   ! a
   $ hg diff
+
+Dirstate should block addition of paths with relative parent components
+  $ hg up -C .
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ ls
+  $ hg debugsh -c "repo.dirstate.add('foo/../b')"
+  abort: cannot add path with relative parents: foo/../b
+  [255]
+  $ touch b
+  $ mkdir foo
+  $ hg add foo/../b
+  $ hg commit -m "add b"
+  $ hg status --change .
+  A b