Add nodefs handling for directories that contain exotic entries

Author: hoodmane

src/library_syscall.js

@@ -717,7 +717,18 @@ var SyscallsLibrary = {
         type = 4; // DT_DIR
       }
       else {
-        var child = FS.lookupNode(stream.node, name);
+        var child;
+        try {
+          child = FS.lookupNode(stream.node, name);
+        } catch (e) {
+          // If the entry is not a directory, file, or symlink, nodefs
+          // lookupNode will raise EINVAL. Skip these and continue.
+          if (e?.errno === {{{ cDefs.EINVAL }}}) {
+            idx += 1;
+            continue;
+          }
+          throw e;
+        }
         id = child.id;
         type = FS.isChrdev(child.mode) ? 2 :  // DT_CHR, character device.
                FS.isDir(child.mode) ? 4 :     // DT_DIR, directory.

test/test_core.py

@@ -5762,6 +5762,7 @@ def test_fs_nodefs_readdir(self):
     # externally setup an existing folder structure: existing/a
     if self.get_setting('WASMFS'):
       self.set_setting('FORCE_FILESYSTEM')
+    os.mkfifo(os.path.join(self.working_dir, 'named_pipe'))
     os.makedirs(os.path.join(self.working_dir, 'existing', 'a'))
     self.emcc_args += ['-lnodefs.js']
     self.do_runf('fs/test_nodefs_readdir.c', 'success')