Correctly handle calls setting timestamp to 0

src/library_memfs.js

@@ -172,7 +172,7 @@ addToLibrary({
       },
       setattr(node, attr) {
         for (const key of ["mode", "atime", "mtime", "ctime"]) {
-          if (attr[key]) {
+          if (typeof attr[key] === 'number') {
             node[key] = attr[key];
           }
         }

src/library_nodefs.js

@@ -166,9 +166,14 @@ addToLibrary({
             // update the common node structure mode as well
             node.mode = attr.mode;
           }
-          if (attr.atime || attr.mtime) {
-            var atime = attr.atime && new Date(attr.atime);
-            var mtime = attr.mtime && new Date(attr.mtime);
+          if (typeof (attr.atime ?? attr.mtime) === "number") {
+            // Unfortunately, we have to stat the current value if we don't want
+            // to change it. On top of that, since the times don't round trip
+            // this will only keep the value nearly unchanged not exactly
+            // unchanged. See:
+            // https://github.com/nodejs/node/issues/56492
+            var atime = new Date(attr.atime ?? fs.lstatSync(NODEFS.realPath(node)).atime);
+            var mtime = new Date(attr.mtime ?? fs.lstatSync(NODEFS.realPath(node)).mtime);
             fs.utimesSync(path, atime, mtime);
           }
           if (attr.size !== undefined) {

src/library_workerfs.js

@@ -91,7 +91,7 @@ addToLibrary({
       },
       setattr(node, attr) {
         for (const key of ["mode", "atime", "mtime", "ctime"]) {
-          if (attr[key]) {
+          if (typeof attr[key] === 'number') {
             node[key] = attr[key];
           }
         }

test/test_core.py

@@ -5571,7 +5571,7 @@ def test_libgen(self):
   def test_utime(self):
     self.do_runf('utime/test_utime.c', 'success')
 
-  @also_with_noderawfs
+  @also_with_nodefs_both
   def test_futimens(self):
     self.do_runf('utime/test_futimens.c', 'success')
 

test/utime/test_futimens.c

@@ -14,6 +14,7 @@
 #include <unistd.h>
 #include <time.h>
 #include <sys/stat.h>
+#include <utime.h>
 
 
 void create_file(const char *path, const char *buffer, int mode) {
@@ -67,7 +68,7 @@ void test() {
   assert(s.st_rdev == 0);
   assert(s.st_size == 8);
   assert(s.st_ctime);
-#if defined(__EMSCRIPTEN__) && !defined(NODERAWFS)
+#if defined(__EMSCRIPTEN__) && !defined(NODERAWFS) && !defined(NODEFS)
   assert(s.st_blksize == 4096);
   assert(s.st_blocks == 1);
 #endif
@@ -128,6 +129,15 @@ void test() {
   times[1].tv_nsec = now.tv_nsec;
   check_times(fd, times, 1);
 
+  printf("check setting time to 0...\n");
+  struct utimbuf tb = {0};
+  utime("folder/file", &tb);
+  times[0].tv_sec = 0;
+  times[0].tv_nsec = 0;
+  times[1].tv_sec = 0;
+  times[1].tv_nsec = 0;
+  check_times(fd, times, 0);
+
   close(fd);
 
   puts("success");