Ensure the ino we give to readdir matches the ino we give to stat

src/library_nodefs.js

@@ -138,7 +138,7 @@ addToLibrary({
         }
         return {
           dev: stat.dev,
-          ino: stat.ino,
+          ino: node.id,
           mode: stat.mode,
           nlink: stat.nlink,
           uid: stat.uid,

test/fs/test_fs_readdir_ino_matches_stat_ino.c

@@ -0,0 +1,76 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#include <dirent.h>
+
+
+#if defined(__EMSCRIPTEN__)
+#include <emscripten.h>
+#endif
+
+void makedir(const char *dir) {
+  int rtn = mkdir(dir, 0777);
+  assert(rtn == 0);
+}
+
+void changedir(const char *dir) {
+  int rtn = chdir(dir);
+  assert(rtn == 0);
+}
+
+void setup() {
+#if defined(__EMSCRIPTEN__) && defined(NODEFS)
+  makedir("working");
+  emscripten_debugger();
+  EM_ASM(FS.mount(NODEFS, { root: '.' }, 'working'));
+  changedir("working");
+#endif
+  mkdir("sub", 0775);
+  changedir("sub");
+}
+
+int main() {
+  setup();
+  int res = open("b", O_CREAT, 0777);
+  assert(res >= 0);
+  assert(close(res) == 0);
+  assert(symlink("b", "a") == 0);
+  int dirfd = open(".", O_RDONLY);
+  assert(dirfd > 0);
+  DIR *dirp;
+  dirp = fdopendir(dirfd);
+  assert(dirp != NULL);
+  struct dirent *ep;
+  struct stat sta, stb;
+  assert(lstat("a", &sta) == 0);
+  assert(lstat("b", &stb) == 0);
+  // Remove execute permission from directory. This prevents us from stat'ing
+  // files in the directory in the implementation of readdir which we tried to
+  // use to fix this.
+  assert(chmod(".", 0675) == 0);
+  int a_ino = -1;
+  int b_ino = -1;
+  while ((ep = readdir(dirp))) {
+    if (strcmp(ep->d_name, "a") == 0) {
+      a_ino = ep->d_ino;
+    }
+    if (strcmp(ep->d_name, "b") == 0) {
+      b_ino = ep->d_ino;
+    }
+  }
+  assert(errno == 0);
+  assert(a_ino >= 0);
+  assert(b_ino >= 0);
+  assert(chmod(".", 0775) == 0);
+  printf("readdir a_ino: %d, b_ino: %d\n", a_ino, b_ino);
+  printf("stat    a_ino: %llu, b_ino: %llu\n", sta.st_ino, stb.st_ino);
+  assert(a_ino == sta.st_ino);
+  assert(b_ino == stb.st_ino);
+  printf("success\n");
+}

test/test_core.py

@@ -5900,6 +5900,16 @@ def test_fs_rename_on_existing(self, args):
       self.set_setting('FORCE_FILESYSTEM')
     self.do_runf('fs/test_fs_rename_on_existing.c', 'success', emcc_args=args)
 
+  @parameterized({
+    '': ([],),
+    'nodefs': (['-DNODEFS', '-lnodefs.js'],),
+    'noderawfs': (['-sNODERAWFS'],)
+  })
+  def test_fs_readdir_ino_matches_stat_ino(self, args):
+    if self.get_setting('WASMFS'):
+      self.set_setting('FORCE_FILESYSTEM')
+    self.do_runf('fs/test_fs_readdir_ino_matches_stat_ino.c', 'success', emcc_args=args)
+
   def test_sigalrm(self):
     self.do_runf('test_sigalrm.c', 'Received alarm!')
     self.set_setting('EXIT_RUNTIME')