From 6f323724ba3daf12fd2c9908f0c23193db39de6d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Golonka?= <wulfryk1@gmail.com>
Date: Mon, 16 Sep 2019 15:15:01 +0200
Subject: [PATCH 1/2] Stop removing compiled Python files from user and system
 configs during update of NVDA.

- In addition remove all .dll and manifest files.
- stop removing mpr.dll explicitly - it is removed along with all other libraries.
---
 source/installer.py | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/source/installer.py b/source/installer.py
index 61fdd30be0e..6284df28468 100644
--- a/source/installer.py
+++ b/source/installer.py
@@ -1,8 +1,8 @@
-#installer.py
-#A part of NonVisual Desktop Access (NVDA)
-#This file is covered by the GNU General Public License.
-#See the file COPYING for more details.
-#Copyright (C) 2011-2019 NV Access Limited, Joseph Lee, Babbage B.V.
+# -*- coding: UTF-8 -*-
+# A part of NonVisual Desktop Access (NVDA)
+# This file is covered by the GNU General Public License.
+# See the file COPYING for more details.
+# Copyright (C) 2011-2019 NV Access Limited, Joseph Lee, Babbage B.V., Łukasz Golonka
 
 from ctypes import *
 from ctypes.wintypes import *
@@ -23,7 +23,7 @@
 import easeOfAccess
 import COMRegistrationFixes
 import winKernel
-import importlib.machinery
+
 _wsh=None
 def _getWSH():
 	global _wsh
@@ -200,20 +200,21 @@ def removeOldProgramFiles(destPath):
 			else:
 				os.remove(fn)
 
-	# #4235: mpr.dll is a Windows system dll accidentally included with
-	# earlier versions of NVDA. Its presence causes problems in Windows Vista.
-	fn = os.path.join(destPath, "mpr.dll")
-	if os.path.isfile(fn):
-		tryRemoveFile(fn)
-
 	# #9960: If compiled python files from older versions aren't removed correctly,
 	# this could cause strange errors when Python tries to create tracebacks
 	# in a newer version of NVDA.
+	#  However don't touch user and system config.
+	#  Also remove old .dll and .manifest files.
 	for curDestDir,subDirs,files in os.walk(destPath):
+		subDirs[:] = [x for x in subDirs if os.path.basename(x).lower() not in (
+			'userconfig',
+			'systemconfig',
+			#  Do not remove old libraries here. It is done by removeOldLibFiles.
+			'lib',
+			'lib64',
+			'libarm64')]
 		for f in files:
-			if f.endswith((".pyc", ".pyo", ".pyd")) and not f.endswith(importlib.machinery.EXTENSION_SUFFIXES[0]):
-				# This also removes compiled files from system config,
-				# but that is fine.
+			if f.endswith((".pyc", ".pyo", ".pyd", ".dll", ".manifest")):
 				path=os.path.join(curDestDir, f)
 				log.debug(f"Removing old byte compiled python file: {path!r}")
 				try:

From 6f5330d6759fe3ef49f821d0c54d52e4177238ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Golonka?= <wulfryk1@gmail.com>
Date: Mon, 21 Oct 2019 16:52:30 +0200
Subject: [PATCH 2/2] Review actions.

---
 source/installer.py | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/source/installer.py b/source/installer.py
index 6284df28468..5878ed7368c 100644
--- a/source/installer.py
+++ b/source/installer.py
@@ -206,13 +206,14 @@ def removeOldProgramFiles(destPath):
 	#  However don't touch user and system config.
 	#  Also remove old .dll and .manifest files.
 	for curDestDir,subDirs,files in os.walk(destPath):
-		subDirs[:] = [x for x in subDirs if os.path.basename(x).lower() not in (
-			'userconfig',
-			'systemconfig',
-			#  Do not remove old libraries here. It is done by removeOldLibFiles.
-			'lib',
-			'lib64',
-			'libarm64')]
+		if curDestDir == destPath:
+			subDirs[:] = [x for x in subDirs if os.path.basename(x).lower() not in (
+				'userconfig',
+				'systemconfig',
+				#  Do not remove old libraries here. It is done by removeOldLibFiles.
+				'lib',
+				'lib64',
+				'libarm64')]
 		for f in files:
 			if f.endswith((".pyc", ".pyo", ".pyd", ".dll", ".manifest")):
 				path=os.path.join(curDestDir, f)