Fix for pathnames with trailing slash

Such paths should be rejected by open / stat / realpath but we were
silently ignoring the tailing slashed.

Fixes: #22335

Author: sbc100

src/library_fs.js

@@ -177,6 +177,7 @@ FS.staticInit();
     // paths
     //
     lookupPath(path, opts = {}) {
+      var trailingSlash = path.endsWith('/');
       path = PATH_FS.resolve(path);
 
       if (!path) return { path: '', node: null };
@@ -233,6 +234,10 @@ FS.staticInit();
         }
       }
 
+      if (trailingSlash && !FS.isDir(current.mode)) {
+        throw new FS.ErrnoError({{{ cDefs.ENOTDIR }}});
+      }
+
       return { path: current_path, node: current };
     },
     getPath(node) {

src/library_path.js

@@ -37,8 +37,8 @@ addToLibrary({
       return parts;
     },
     normalize: (path) => {
-      var isAbsolute = PATH.isAbs(path),
-          trailingSlash = path.substr(-1) === '/';
+      var isAbsolute = PATH.isAbs(path);
+      var trailingSlash = path.endsWith('/');
       // Normalize the path
       path = PATH.normalizeArray(path.split('/').filter((p) => !!p), !isAbsolute).join('/');
       if (!path && !isAbsolute) {

system/lib/wasmfs/paths.cpp

@@ -75,11 +75,6 @@ ParsedParent doParseParent(std::string_view path,
     path.remove_prefix(1);
   }
 
-  // Ignore trailing '/'.
-  while (!path.empty() && path.back() == '/') {
-    path.remove_suffix(1);
-  }
-
   // An empty path here means that the path was equivalent to "/" and does not
   // contain a child segment for us to return. The root is its own parent, so we
   // can handle this by returning (root, ".").

test/other/metadce/test_metadce_files_wasmfs.funcs

@@ -31,7 +31,9 @@ $__wasm_call_ctors
 $abort
 $char*\20std::__2::copy_n\5babi:nn180100\5d<char\20const*\2c\20unsigned\20long\2c\20char*\2c\200>\28char\20const*\2c\20unsigned\20long\2c\20char*\29
 $decltype\28auto\29\20std::__2::__variant_detail::__visitation::__base::__dispatcher<0ul>::__dispatch\5babi:nn180100\5d<std::__2::__variant_detail::__dtor<std::__2::__variant_detail::__traits<std::__2::vector<wasmfs::Directory::Entry\2c\20std::__2::allocator<wasmfs::Directory::Entry>>\2c\20int>\2c\20\28std::__2::__variant_detail::_Trait\291>::__destroy\5babi:nn180100\5d\28\29::'lambda'\28auto&\29&&\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20std::__2::vector<wasmfs::Directory::Entry\2c\20std::__2::allocator<wasmfs::Directory::Entry>>\2c\20int>&>\28auto\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20std::__2::vector<wasmfs::Directory::Entry\2c\20std::__2::allocator<wasmfs::Directory::Entry>>\2c\20int>&\29
+$decltype\28auto\29\20std::__2::__variant_detail::__visitation::__base::__dispatcher<0ul\2c\200ul>::__dispatch\5babi:nn180100\5d<void\20std::__2::__variant_detail::__ctor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>>::__generic_construct\5babi:nn180100\5d<std::__2::__variant_detail::__move_constructor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>>\28std::__2::__variant_detail::__ctor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>>&\2c\20std::__2::__variant_detail::__move_constructor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>&&\29::'lambda'\28std::__2::__variant_detail::__move_constructor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>&\2c\20auto&&\29&&\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&&>\28std::__2::__variant_detail::__move_constructor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&&\29
 $decltype\28auto\29\20std::__2::__variant_detail::__visitation::__base::__dispatcher<1ul>::__dispatch\5babi:nn180100\5d<std::__2::__variant_detail::__dtor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>::__destroy\5babi:nn180100\5d\28\29::'lambda'\28auto&\29&&\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&>\28auto\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&\29
+$decltype\28auto\29\20std::__2::__variant_detail::__visitation::__base::__dispatcher<1ul\2c\201ul>::__dispatch\5babi:nn180100\5d<void\20std::__2::__variant_detail::__ctor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>>::__generic_construct\5babi:nn180100\5d<std::__2::__variant_detail::__move_constructor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>>\28std::__2::__variant_detail::__ctor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>>&\2c\20std::__2::__variant_detail::__move_constructor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>&&\29::'lambda'\28std::__2::__variant_detail::__move_constructor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>&\2c\20auto&&\29&&\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&&>\28std::__2::__variant_detail::__move_constructor<std::__2::__variant_detail::__traits<long\2c\20std::__2::shared_ptr<wasmfs::File>>\2c\20\28std::__2::__variant_detail::_Trait\291>\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&\2c\20std::__2::__variant_detail::__base<\28std::__2::__variant_detail::_Trait\291\2c\20long\2c\20std::__2::shared_ptr<wasmfs::File>>&&\29
 $dummy
 $emscripten_builtin_malloc
 $fflush

test/other/metadce/test_metadce_files_wasmfs.size

@@ -1 +1 @@
-50957
+51335

test/other/test_realpath_2.c

@@ -20,6 +20,8 @@ int main(int argc, char **argv) {
   testrealpath("testfile.txt");
   testrealpath("Folder/testfile.txt");
   testrealpath("testnonexistentfile.txt");
+  // Filenames with trailing slash should fail.
+  testrealpath("Folder/testfile.txt/");
   // folders
   testrealpath("Folder");
   testrealpath("/Folder");

test/other/test_realpath_2.out

@@ -1,6 +1,7 @@
 Resolved: "testfile.txt" => "/testfile.txt"
 Resolved: "Folder/testfile.txt" => "/Folder/testfile.txt"
 Resolve failed: "testnonexistentfile.txt"
+Resolve failed: "Folder/testfile.txt/"
 Resolved: "Folder" => "/Folder"
 Resolved: "/Folder" => "/Folder"
 Resolved: "./" => "/"

test/wasmfs/wasmfs_open.c

@@ -16,13 +16,15 @@
 // FIXME: Merge with other existing close and open tests.
 
 int main() {
-  // Test writing to a file with a trailing slash.
+  // Opening a file with trailing backslash should fail.
   int fd = open("/dev/stdout/", O_WRONLY);
-
-  dprintf(fd, "WORKING WITH TRAILING BACKSLASH\n");
-
-  // Close open file
-  close(fd);
+  assert(fd == -1);
+#ifdef WASMFS
+  assert(errno == ENOTDIR);
+#else
+  assert(errno == ENOENT);
+#endif
+  printf("Errno: %s\n", strerror(errno));
 
   // Test writing to a file with no trailing backslash.
   int fd2 = open("/dev/stdout", O_WRONLY);

test/wasmfs/wasmfs_open.out

@@ -1,4 +1,3 @@
-WORKING WITH TRAILING BACKSLASH
 WORKING WITHOUT TRAILING BACKSLASH
 Errno: Bad file descriptor
 Errno: Is a directory

test/wasmfs/wasmfs_stat.c

@@ -25,9 +25,13 @@ int main() {
   assert(result == -1);
   assert(errno == EBADF);
 
+  // Test stat of file with trailing slash should fail.
+  assert(stat("/dev/stdout/", &invalid) == -1);
+  assert(errno == ENOTDIR);
+
   // Test opening a file and calling fstat.
   struct stat file;
-  int fd = open("/dev/stdout/", O_WRONLY);
+  int fd = open("/dev/stdout", O_WRONLY);
   assert(fd >= 0);
   assert(fstat(fd, &file) != -1);
 
@@ -48,7 +52,7 @@ int main() {
   close(fd);
 
   // Check to see if the previous inode number matches.
-  int newfd = open("/dev/stdout/", O_WRONLY);
+  int newfd = open("/dev/stdout", O_WRONLY);
   struct stat newFile;
   assert(newfd >= 0);
   assert(fstat(newfd, &newFile) != -1);
@@ -95,7 +99,7 @@ int main() {
 
   // Test calling stat without opening a file.
   struct stat statFile;
-  assert(stat("/dev/stdout/", &statFile) != -1);
+  assert(stat("/dev/stdout", &statFile) != -1);
 
   assert(statFile.st_size == 0);
   assert((statFile.st_mode & S_IFMT) == S_IFCHR);