Added a workaround for GetFileInformationByHandleEx error in dir iterator.

Reproduce the workaround for GetFileInformationByHandleEx returning
ERROR_INVALID_PARAMETER when querying FILE_ATTRIBUTE_TAG_INFO on FAT/exFAT
filesystems in directory iterator construction.

Fixes boostorg#237.

Author: Lastique

doc/release_history.html

@@ -42,7 +42,7 @@
 <h2>1.80.0</h2>
 <ul>
   <li>On Windows, added a fallback implementation for querying file attributes in case if the file cannot be opened with <code>ERROR_ACCESS_DENIED</code> error. This may allow <code>status</code> and <code>symlink_status</code> to succeed for system files and directories that are not reparse points or symlinks. (<a href="https://github.com/boostorg/filesystem/issues/234">#234</a>)</li>
-  <li>On Windows, added a workaround for <code>status</code> and <code>symlink_status</code> reporting that files do not exist on FAT/exFAT filesystems. (<a href="https://github.com/boostorg/filesystem/issues/236">#236</a>)</li>
+  <li>On Windows, added a workaround for FAT/exFAT filesystems that produce <code>ERROR_INVALID_PARAMETER</code> when querying file attributes. This affected <code>status</code> and <code>symlink_status</code>, which reported that files do not exist, and directory iterators, which failed to construct, as well as other dependent operations. (<a href="https://github.com/boostorg/filesystem/issues/236">#236</a>, <a href="https://github.com/boostorg/filesystem/issues/237">#237</a>)</li>
 </ul>
 
 <h2>1.79.0</h2>

src/directory.cpp

@@ -774,7 +774,14 @@ error_code dir_itr_create(boost::intrusive_ptr< detail::dir_itr_imp >& imp, fs::
         file_attribute_tag_info info;
         BOOL res = get_file_information_by_handle_ex(h.handle, file_attribute_tag_info_class, &info, sizeof(info));
         if (BOOST_UNLIKELY(!res))
-            goto return_last_error;
+        {
+            // On FAT/exFAT filesystems requesting FILE_ATTRIBUTE_TAG_INFO returns ERROR_INVALID_PARAMETER. See the comment in symlink_status.
+            DWORD error = ::GetLastError();
+            if (error == ERROR_INVALID_PARAMETER || error == ERROR_NOT_SUPPORTED)
+                goto use_get_file_information_by_handle;
+
+            return error_code(error, system_category());
+        }
 
         if (BOOST_UNLIKELY((info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY) == 0u))
             return make_error_code(system::errc::not_a_directory);
@@ -787,6 +794,7 @@ error_code dir_itr_create(boost::intrusive_ptr< detail::dir_itr_imp >& imp, fs::
     }
     else
     {
+    use_get_file_information_by_handle:
         BY_HANDLE_FILE_INFORMATION info;
         BOOL res = ::GetFileInformationByHandle(h.handle, &info);
         if (BOOST_UNLIKELY(!res))

src/operations.cpp

@@ -3770,12 +3770,20 @@ file_status status(path const& p, error_code* ec)
             file_attribute_tag_info info;
             BOOL res = get_file_information_by_handle_ex(h.handle, file_attribute_tag_info_class, &info, sizeof(info));
             if (BOOST_UNLIKELY(!res))
-                goto return_status_failure;
+            {
+                // See the comment in symlink_status
+                DWORD err = ::GetLastError();
+                if (err == ERROR_INVALID_PARAMETER || err == ERROR_NOT_SUPPORTED)
+                    goto use_get_file_information_by_handle;
+
+                return process_status_failure(err, p, ec);
+            }
 
             attrs = info.FileAttributes;
         }
         else
         {
+        use_get_file_information_by_handle:
             BY_HANDLE_FILE_INFORMATION info;
             BOOL res = ::GetFileInformationByHandle(h.handle, &info);
             if (BOOST_UNLIKELY(!res))