From da530f135e4181d473cc5e72e51e4c52ee079bca Mon Sep 17 00:00:00 2001
From: Athanasius <Athanasius@miggy.org>
Date: Thu, 17 Nov 2022 20:52:25 +0000
Subject: [PATCH] prefs.py: Attempting to fix non-utf-8 case of "choose Output
 file location"

1. `SHGetPathFromIDListW` needing fixing, which was achieved, but...
2. ... then `SHBrowseForFolderW()` as-was returned `int` instead of a pointer
  to the correct structure.

Trying to fix 2 has proven intractable:

a. Trying to cast the `int` return just results in `exception: access violation
  reading <address>`.
b. Trying to define `SHBrowseForFolderW` properly, so it returns the correct
  type results in a *writing* access violation when called, despite passing
  the exact same data in as for the 'raw' call version.

So, this commit is a record, and I'm next going to try switching to
`IFileDialog` as recommended by the docs for `SHBrowseForFolderW` ('For
Windows Vista or later').
---
 prefs.py | 81 ++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 70 insertions(+), 11 deletions(-)

diff --git a/prefs.py b/prefs.py
index e5ab242b..e4964785 100644
--- a/prefs.py
+++ b/prefs.py
@@ -181,7 +181,10 @@ if sys.platform == 'darwin':
 elif sys.platform == 'win32':
     import ctypes
     import winreg
-    from ctypes.wintypes import HINSTANCE, HWND, LPARAM, LPCWSTR, LPVOID, LPWSTR, MAX_PATH, POINT, RECT, SIZE, UINT
+    from ctypes import POINTER, WINFUNCTYPE, Structure
+    from ctypes.wintypes import (
+        BOOL, BYTE, HINSTANCE, HWND, LPARAM, LPCWSTR, LPWSTR, MAX_PATH, POINT, RECT, SIZE, UINT, USHORT
+    )
     is_wine = False
     try:
         WINE_REGISTRY_KEY = r'HKEY_LOCAL_MACHINE\Software\Wine'
@@ -192,18 +195,68 @@ elif sys.platform == 'win32':
     except OSError:
         pass
 
+    ###########################################################################
+    # From <https://github.com/hakril/PythonForWindows/blob/master/windows/generated_def/winstructs.py>
+    class _SHITEMID(ctypes.Structure):
+        _fields_ = [
+            ("cb", USHORT),
+            ("abID", BYTE * (1)),
+        ]
+
+    SHITEMID = _SHITEMID
+
+    class _ITEMIDLIST(Structure):
+        _fields_ = [
+            ("mkid", SHITEMID),
+        ]
+
+    ITEMIDLIST = _ITEMIDLIST
+    PCIDLIST_ABSOLUTE = ctypes.POINTER(_ITEMIDLIST)
+    PIDLIST_ABSOLUTE = ctypes.POINTER(_ITEMIDLIST)
+    ###########################################################################
+
+    ###########################################################################
+    # From: <https://stackoverflow.com/questions/32979525/creating-choose-folder-dialog-from-python-using-windows-api>
+    BrowseCallbackProc = WINFUNCTYPE(ctypes.c_int, HWND, ctypes.c_uint, LPARAM, LPARAM)
+
+    class BROWSEINFOW(ctypes.Structure):
+        """
+        Windows file browser fields.
+
+        Ref: <https://learn.microsoft.com/en-us/windows/win32/api/shlobj_core/ns-shlobj_core-browseinfow>
+        """
+
+        _fields_ = [
+            ("hwndOwner", HWND),
+            ("pidlRoot", PCIDLIST_ABSOLUTE),
+            ("pszDisplayName", LPWSTR),
+            ("lpszTitle", LPCWSTR),
+            ("ulFlags", UINT),
+            ("lpfn", BrowseCallbackProc),
+            ("lParam", LPARAM),
+            ("iImage", ctypes.c_int)
+        ]
+    LPBROWSEINFOW = POINTER(BROWSEINFOW)
+    ###########################################################################
+
     # https://msdn.microsoft.com/en-us/library/windows/desktop/bb762115
     BIF_RETURNONLYFSDIRS = 0x00000001
     BIF_USENEWUI = 0x00000050
     BFFM_INITIALIZED = 1
     BFFM_SETSELECTION = 0x00000467
-    BrowseCallbackProc = ctypes.WINFUNCTYPE(ctypes.c_int, HWND, ctypes.c_uint, LPARAM, LPARAM)
+    # SHGetPathFromIDListW
+    # Ref: <https://learn.microsoft.com/en-us/windows/win32/api/shlobj_core/nf-shlobj_core-shgetpathfromidlistw>
+    # BOOL SHGetPathFromIDListW([in]  PCIDLIST_ABSOLUTE pidl,[out] LPWSTR pszPath);
+    prototype = WINFUNCTYPE(BOOL, PCIDLIST_ABSOLUTE, LPCWSTR)
+    paramflags = (1, "pidl"), (2, "pszPath", "")
+    SHGetPathFromIDListW = prototype(("SHGetPathFromIDListW", ctypes.windll.shell32), paramflags)
 
-    class BROWSEINFO(ctypes.Structure):
-        """Windows file browser fields."""
-
-        _fields_ = [("hwndOwner", HWND), ("pidlRoot", LPVOID), ("pszDisplayName", LPWSTR), ("lpszTitle", LPCWSTR),
-                    ("ulFlags", UINT), ("lpfn", BrowseCallbackProc), ("lParam", LPCWSTR), ("iImage", ctypes.c_int)]
+    # SHBrowseForFolderW
+    # Ref: <https://learn.microsoft.com/en-us/windows/win32/api/shlobj_core/nf-shlobj_core-shbrowseforfolderw>
+    # PIDLIST_ABSOLUTE SHBrowseForFolderW([in] LPBROWSEINFOWW lpbi);
+    prototype = WINFUNCTYPE(PIDLIST_ABSOLUTE, LPBROWSEINFOW)
+    paramflags2 = (1, "lpbi"),
+    SHBrowseForFolderW = prototype(("SHGetPathFromIDListW", ctypes.windll.shell32), paramflags2)
 
     CalculatePopupWindowPosition = None
     if not is_wine:
@@ -1037,17 +1090,23 @@ class PreferencesDialog(tk.Toplevel):
                     ctypes.windll.user32.SendMessageW(hwnd, BFFM_SETSELECTION, 1, lpData)
                 return 0
 
-            browseInfo = BROWSEINFO()  # noqa: N806 # Windows convention
+            browseInfo = BROWSEINFOW()  # noqa: N806 # Windows convention
+            # browseInfo.pidlRoot = None
+            browseInfo.pszDisplayName = ctypes.c_wchar_p("x" * MAX_PATH)
             browseInfo.lpszTitle = title
             browseInfo.ulFlags = BIF_RETURNONLYFSDIRS | BIF_USENEWUI
             browseInfo.lpfn = BrowseCallbackProc(browsecallback)
-            browseInfo.lParam = pathvar.get().startswith('~') and join(config.home_path,
-                                                                       pathvar.get()[2:]) or pathvar.get()
+            # browseInfo.lParam = pathvar.get().startswith('~') and join(config.home_path,
+            #                                                            pathvar.get()[2:]) or pathvar.get()
             ctypes.windll.ole32.CoInitialize(None)
             pidl = ctypes.windll.shell32.SHBrowseForFolderW(ctypes.byref(browseInfo))
+            # ctypes.ArgumentError: argument 1: <class 'TypeError'>: expected LP__ITEMIDLIST instance instead of int
+            # pidl = SHBrowseForFolderW(ctypes.byref(browseInfo))
+            # OSError: exception: access violation writing 0x00007FFB582DC9BF
             if pidl:
+                pidl = ctypes.cast(pidl, PIDLIST_ABSOLUTE)
                 path = ctypes.create_unicode_buffer(MAX_PATH)
-                ctypes.windll.shell32.SHGetPathFromIDListW(pidl, path)
+                path = SHGetPathFromIDListW(pidl)
                 ctypes.windll.ole32.CoTaskMemFree(pidl)
                 directory = path.value
             else: