SHParseDisplayName fails with ERROR_FILE_NOT_FOUND when passed existing directory whose name ends with a space character - windows

Question

I'm developing a file manager application, and noticed that some functions don't work with an existing folder that ends with a space symbol. E. g. "E:\1 \". This isn't specific to this particular folder, but indeed to any one with a space as the last character of the folder's name. For such folders, SHParseDisplayName returns ERROR_FILE_NOT_FOUND.
I'm calling SHParseDisplayName like so from C++:
ITEMIDLIST* idPtr = nullptr;
const auto result = SHParseDisplayName(L"E:\\1 \\", nullptr, &idPtr, 0, nullptr);
The documentation doesn't specify any edge cases, nor any ways in which the input path should be pre-processed. Regardless, I tried decorating it with quotes:
SHParseDisplayName(L"\"E:\\1 \\\"", nullptr, &idPtr, 0, nullptr);
And supplying a UNC path:
SHParseDisplayName(L"\\\\?\\E:\\1 \\", nullptr, &idPtr, 0, nullptr);
Both of which results in E_INVALIDARG.
Of note: SHParseDisplayName does work properly for items nested inside such a folder, e. g. L"E:\\1 \\some_internal_folder\\", just not the folder whose name ends with a space itself.
Is there any workaround? Windows Explorer seems to work just fine with such folders (as one would expect).
Also, SHParseDisplayName isn't the only Windows API function that fails for such folders. Another example of the same behavior is ILCreateFromPathW.

Answer 1

File and Folder names that begin or end with the ASCII Space (0x20)
will be saved without these characters. File and Folder names that end
with the ASCII Period (0x2E) character will also be saved without this
character. All other trailing or leading whitespace characters are
retained.
The Win32 API (CreateFile, FindFirstFile, etc.) uses a direct method
to enumerate the files and folders on a local or remote file system.
All files and folders are discoverable regardless of the inclusion or
location of whitespace characters.
Refer to "Support for Whitespace characters in File and Folder names"
And blog "MS-DOS also allowed spaces in file names, although vanishingly few programs knew how to access them.
So for existing files/folders with space at the end of names, either use Win32 API (CreateFile, FindFirstFile, etc.) or replace them with a new name without trailing or leading whitespace characters.