Avoid modifying shared DLL objects

[moi15moi]

Currently, comtypes modifies shared DLL objects. Below are examples where such modifications occur:

• _comobject.py, lines 80–83
• _safearray.py, lines 49–103
• automation.py, lines 586–588

As noted in this comment, it is preferable to use ctypes.WinDLL instead of ctypes.windll. This approach avoids modifying shared DLL objects and ensures better isolation.

[junkmd]

+1.

Feel free to open PRs.

[moi15moi]

Here is a summary of the remaining files that need to be corrected:

• bstr.py - A PR has been open [_post_coinit\bstr.py] Use WinDLL instead of windll #771
  Note that I don't really know how we can do it because if I put this code before the definition of the class, BSTR doesn't exist and if I put it after, _SysFreeString in _free: Callable[["BSTR"], Any] isn't defined:

_oleaut32 = WinDLL("oleaut32")

_SysFreeString = _oleaut32.SysFreeString
_SysFreeString.argtypes = [BSTR]
_SysFreeString.restype = None

• test_basic.py - A PR has been opened [test\test_basic.py] Use OleDLL instead of windll #764
• test_BSTR.py
• test_outparam.py - A PR has been opened [test\test_outparam.py] Use WinDLL/OleDLL instead of windll/oledll #765
• test_urlhistory.py - A PR has been opened [test\test_urlhistory.py] Use WinDLL instead of windll #766
• tlbparser.py - A PR has been opened [tools\tlbparser.py] Import QueryPathOfRegTypeLib from typeinfo + doc adjustments #763
• test_comobject.py - A PR has been opened [test\test_comobject.py] Use OleDLL instead of oledll #767
• test_stream.py - A PR has been opened [test\test_stream.py] Use OleDLL instead of oledll #768
• server/init.py - A PR has been opened [server\__init__.py] Use OleDLL instead of oledll #769
• init.py - A PR has been opened [__init__.py] Use WinDLL/OleDLL instead of windll/oledll #770
• test_monikers.py
• test_storage.py

[junkmd]

• test_basic.py - A PR has been opened [test\test_basic.py] Use OleDLL instead of windll #764
• test_BSTR.py
• test_outparam.py - A PR has been opened [test\test_outparam.py] Use WinDLL/OleDLL instead of windll/oledll #765
• test_urlhistory.py - A PR has been opened [test\test_urlhistory.py] Use WinDLL instead of windll #766
• tlbparser.py - A PR has been opened [tools\tlbparser.py] Import QueryPathOfRegTypeLib from typeinfo + doc adjustments #763
• test_comobject.py - A PR has been opened [test\test_comobject.py] Use OleDLL instead of oledll #767
• test_stream.py - A PR has been opened [test\test_stream.py] Use OleDLL instead of oledll #768
• server/init.py - A PR has been opened [server\__init__.py] Use OleDLL instead of oledll #769
• init.py - A PR has been opened [__init__.py] Use WinDLL/OleDLL instead of windll/oledll #770

What about test_monikers and test_storage?

[junkmd]

• bstr.py
  Note that I don't really know how we can do it because if I put this code before the definition of the class, BSTR doesn't exist and if I put it after, _SysFreeString in _free: Callable[["BSTR"], Any] isn't defined:

Have you tried this approach?

+_oleaut32 = WinDLL("oleaut32")
+
+_SysFreeString = _oleaut32.SysFreeString
+
+
 class BSTR(_SimpleCData):
     """The windows BSTR data type"""

@@ -18,9 +23,7 @@ class BSTR(_SimpleCData):
         self._needsfree = True
         return self.value

-    def __del__(
-        self, _free: Callable[["BSTR"], Any] = windll.oleaut32.SysFreeString
-    ) -> None:
+    def __del__(self, _free: Callable[["BSTR"], Any] = _SysFreeString) -> None:
         # Free the string if self owns the memory
         # or if instructed by __ctypes_from_outparam__.
         if self._b_base_ is None or self._needsfree:
@@ -35,3 +38,7 @@ class BSTR(_SimpleCData):
         # right thing, it doesn't ensure that SysFreeString is called
         # on destruction.
         return cls(value)
+
+
+_SysFreeString.argtypes = [BSTR]
+_SysFreeString.restype = None