Backed out changeset eb32954c1f4c (bug 1769094) for causing multiple failures.

xpcom/io/nsIFile.idl

@@ -69,9 +69,8 @@ interface nsIFile : nsISupports
      *
      *   @param node
      *       A string which is intended to be a child node of the nsIFile.
-     *       For security reasons, this cannot contain .. and cannot start with
-     *       a directory separator. For the |appendNative| method, the node must
-     *       be in the native filesystem charset.
+     *       For the |appendNative| method, the node must be in the native
+     *       filesystem charset.
      */
     void append(in AString node);
     [noscript] void appendNative(in ACString node);
@@ -464,7 +463,7 @@ interface nsIFile : nsISupports
      *
      *   @param relativeFilePath
      *       relativeFilePath is a native relative path. For security reasons,
-     *       this cannot contain .. and cannot start with a directory separator.
+     *       this cannot contain .. or cannot start with a directory separator.
      *       For the |appendRelativeNativePath| method, the relativeFilePath
      *       must be in the native filesystem charset.
      */

xpcom/io/nsLocalFileUnix.cpp

@@ -560,10 +560,9 @@ nsLocalFile::AppendNative(const nsACString& aFragment) {
     return NS_OK;
   }
 
-  // only one component of path can be appended and cannot append ".."
+  // only one component of path can be appended
   nsACString::const_iterator begin, end;
-  if (aFragment.EqualsASCII("..") ||
-      FindCharInReadable('/', aFragment.BeginReading(begin),
+  if (FindCharInReadable('/', aFragment.BeginReading(begin),
                          aFragment.EndReading(end))) {
     return NS_ERROR_FILE_UNRECOGNIZED_PATH;
   }
@@ -577,35 +576,11 @@ nsLocalFile::AppendRelativeNativePath(const nsACString& aFragment) {
     return NS_OK;
   }
 
-  // No leading '/' and cannot be ".."
-  if (aFragment.First() == '/' || aFragment.EqualsASCII("..")) {
+  // No leading '/'
+  if (aFragment.First() == '/') {
     return NS_ERROR_FILE_UNRECOGNIZED_PATH;
   }
 
-  if (aFragment.Contains('/')) {
-    // can't contain .. as a path component. Ensure that the valid components
-    // "foo..foo", "..foo", and "foo.." are not falsely detected,
-    // but the invalid paths "../", "foo/..", "foo/../foo",
-    // "../foo", etc are.
-    constexpr auto doubleDot = "/.."_ns;
-    nsACString::const_iterator start, end, offset;
-    aFragment.BeginReading(start);
-    aFragment.EndReading(end);
-    offset = end;
-    while (FindInReadable(doubleDot, start, offset)) {
-      if (offset == end || *offset == '/') {
-        return NS_ERROR_FILE_UNRECOGNIZED_PATH;
-      }
-      start = offset;
-      offset = end;
-    }
-
-    // catches the remaining cases of prefixes
-    if (StringBeginsWith(aFragment, "../"_ns)) {
-      return NS_ERROR_FILE_UNRECOGNIZED_PATH;
-    }
-  }
-
   if (!mPath.EqualsLiteral("/")) {
     mPath.Append('/');
   }

xpcom/tests/unit/test_localfile.js

@@ -183,27 +183,3 @@ add_task(
     file.remove(true);
   }
 );
-
-add_task(function test_file_append_parent() {
-  const SEPARATOR = AppConstants.platform === "win" ? "\\" : "/";
-
-  const file = do_get_profile();
-
-  Assert.throws(
-    () => file.append(".."),
-    /NS_ERROR_FILE_UNRECOGNIZED_PATH/,
-    `nsLocalFile::Append("..") throws`
-  );
-
-  Assert.throws(
-    () => file.appendRelativePath(".."),
-    /NS_ERROR_FILE_UNRECOGNIZED_PATH/,
-    `nsLocalFile::AppendRelativePath("..") throws`
-  );
-
-  Assert.throws(
-    () => file.appendRelativePath(`foo${SEPARATOR}..${SEPARATOR}baz`),
-    /NS_ERROR_FILE_UNRECOGNIZED_PATH/,
-    `nsLocalFile::AppendRelativePath(path) fails when path contains ".."`
-  );
-});