Fix multiple inplementation errors including the incorrect usage of S_FALSE.
Make this function behave like the Windows 8 implementation and
the according MSDN specification.
- return S_OK if the extension was NOT found
- if no extension was found, ppszExt must point to the string's terminating null
- return E_INVALIDARG if pszPath is not null-terminated within the cchPath range
- return E_INVALIDARG if pszPath is NULL
- return E_INVALIDARG if ppszExt is NULL
- return E_INVALIDARG if cchPath is Zero
- return E_NOTIMPL instead of S_OK in PathPathCchFindExtensionW()
Also extended/fixed the TestPathCchFindExtension ctest
And again S_FALSE was incorrectly used to indicate an error.
Fix this and be more compatible to the Windows 8 implementation of
this function:
- return E_INVALIDARG instead of S_FALSE if pszPath is NULL
- return E_INVALIDARG instead of S_FALSE if cchPath < 4
- return E_INVALIDARG if cchPath > PATHCCH_MAX_CCH
- allow stripping of "\\?\c:" and don't require "\\?\c:\"
- verify that the character at the drive letter position is
actually an alphabetic character
- since the passed pszPath must not necessarily be null terminated
and we always have enough space after the memmove we can always
ensure the null termination of the stripped result
Also extended/fixed the TestPathCchStripPrefixctest
