Provide a tool to re-register particular COM interfaces that may become unregistered or broken by uninstallers, breaking platform accessibility #8075

michaelDCurran · 2018-03-12T02:41:46Z

Link to issue number:

Summary of the issue:

Installers for products such as Adobe Reader and MathPlayer, incorrectly register their own dlls/typelibs as the COM proxy for certain COM interfaces such as IAccessible, IDispatch, IEnumVARIANT or IServiceProvider. While installed, there is no user impact, however once the product is uninstalled, the original registration is not put back and the registry is now pointing to a missing COM proxy for these interfaces. This causes these interfaces to be not marshallable and therefore accessibility is completely broken in software such as Firefox, chrome, Internet Explorer, and even some core parts of Windows such as the Task bar.

Description of how this pull request fixes the issue:

Based on the research provided by @jcsteh in #2807, this PR adds a tool to NVDA that re-registers the affected COM interfaces with their correct Windows-provided COM proxy dlls.
The tool automatically runs at the end of NVDA installation, but is also available from the Tools menu.

Testing performed:

On windows 10:

Manually edited the registry to point IAccessible and IDispatch to non-existant COM proxies.
Confirmed that accessibility was broken: Could not use Internet Explorer documents at all.
Installed NVDA to successfully correct the COM interfaces.
Could again use Internet Explorer
On Windows 7:
Installed Adobe Reader
Uninstalled Adobe Reader
Confirmed that accessibility was broken: Could not use Internet Explorer documents at all.
Installed NVDA to successfully correct the COM interfaces.
Could again use Internet Explorer

Known issues with pull request:

This should fix all the cases we are aware of where following the instructions in #2807 fixed problems for people. There could be other COM interfaces that get broken that we don't yet know about. But these could be added to the tool in future once we have evidence of a fix.

Change log entry:

Bug fixes:

NVDA will now try to correct system COM registration issues causing programs such as Firefox and Internet Explorer to become inaccessible and report "Unknown" by NVDA. (NVDA stops reading webpages in all browser - saying "unknown" or "pane" #2807)

…broken by bad uninstallers.

…eremove some unused functions.

LeonarddeR · 2018-03-12T04:58:57Z

I wonder whether it is preferred here to have a confirmation question before the tool runs. Also, could you please commit the reg files as textual files rather than binary?

michaelDCurran · 2018-03-12T05:05:10Z

I can add a confirmation dialog. The reg files are text, but I guess they are in 16 bit Unicode. They are certainly readable with Notepad.

jcsteh · 2018-03-12T05:07:14Z

@leonardder commented on Mar 12, 2018, 2:58 PM GMT+10:

I wonder whether it is preferred here to have a confirmation question before the tool runs.

That's tricky. It will always run at install time... and we really don't want to ask the user at that point because it should just happen without the user needing to understand it. We're not doing anything that shouldn't actually already be done on a non-broken system. As to whether to do it when you manually run the tool, I suppose I can see why you'd want to do that... but on the other hand, if we're not asking at install time, why ask here? Note that you'll get asked for UAC elevation, so you can always say no at that point.

Also, could you please commit the reg files as textual files rather than binary?

As Mick noted, they're already text, but UTF-16, which git doesn't recognise as text. Unfortunately, this is what regedit does natively. Regedit does support another format which is 8 bit instead of 16 bit, but that is labelled "Win9x/NT4 Registration Files", which raises some unanswered questions about what you lose when you use that.

…ually from the Tools menu.

feerrenrut · 2018-03-12T05:14:20Z

source/COMRegistrationFixes/__init__.py

@@ -0,0 +1,68 @@
+import os


Could you add a copyright header.

Also perhaps a docstring for this package.

feerrenrut · 2018-03-12T06:46:12Z

source/COMRegistrationFixes/__init__.py

+	if OSMajorMinor==(6,1): # Windows 7
+		registerServer(os.path.join(programFiles,'Internet Explorer','ieproxy.dll'))
+		if is64bit:
+			registerServer(os.path.join(programFilesX86,'Internet Explorer','ieproxy.dll'),wow64=True)


If its 64 bit windows 7 then register the ieproxy.dll from both "program files/internet explorer/" and "program files (x86)/internet explorer"?

Correct. There are COM proxies for both 64 bit and 32 bit on 64 bit machines. The first registration will be 32 bit on 32 bit machines and 64 bit on 64 bit machines. Then if the machine is 64 bit, we also need to register the 32 bit one, so that 32 bit apps (including NVDA) can work. Note that IServiceProvider is used in more places than just Internet Explorer, its just that MS chose to store it in ieproxy.dll on Windows 7.

feerrenrut · 2018-03-12T06:49:04Z

source/setup.py

@@ -114,7 +114,7 @@ def run(self):

 	def build_manifest(self, target, template):
 		mfest, rid = build_exe.py2exe.build_manifest(self, target, template)
-		if getattr(target, "script", None) == "nvda.pyw":
+		if getattr(target, "script", "").endswith(".pyw"):


what is this change about?

LeonarddeR · 2018-03-12T07:36:32Z

source/COMRegistrationFixes/__init__.py

+	OSMajorMinor=winVersion.winVersion[:2]
+	log.debug("Fixing COM registration for Windows %s.%s, %s"%(OSMajorMinor[0],OSMajorMinor[1],"64 bit" if is64bit else "32 bit"))  
+	# Commands taken from NVDA issue #2807 comment https://github.com/nvaccess/nvda/issues/2807#issuecomment-320149243
+	# OLEACC (MSAA) proxies


I assume this implies registering oleacc.dll doesn't have the desired result?

Correct. See @jcsteh's comment in #2807 on this: #2807 (comment)

Brian1Gaff · 2018-03-16T10:02:32Z

Hi, today on the users list there are several people after a recent windows update who say this tool does not fix the non reading issues of web pages and some other screen content, however the fix Gene mentions from a recent ticket when applied seems to be working. In my case it was windows 7 and it fixed it after the update when I ran the tool, but uac is off. I'm just bringing it to your attention in case nobody feels able to post to the issue, you can go and have a look. I saw three threads on this, and it seems an update this week from Microsoft is the cause, but not everyone is affected it seems.

Qchristensen · 2018-03-16T21:57:56Z

I noticed in this build that the NVDA icon has reverted to the old one, was that deliberate? My bigger concern was just in case more critical things have been rolled back since the icon change was done awhile ago.

LeonarddeR · 2018-03-17T08:00:32Z

@Qchristensen commented on 16 mrt. 2018 22:57 CET:

I noticed in this build that the NVDA icon has reverted to the old one, was that deliberate? My bigger concern was just in case more critical things have been rolled back since the icon change was done awhile ago.

See #8091.

It might be more likely that #7104 is the cause of this, since that pr also involves changes in misc deps.

Qchristensen · 2018-03-17T09:04:20Z

Yes it looks like that might have been it since I realised after writing this that the change happened in 14945 which incubated #7104

This happened to still work on x64 as there is a 32 bit copy of regedit in c:\windows\syswow64, and as NVDA itself is 32 bit it always found it. Fixes #8089

LeonarddeR · 2018-03-29T12:29:27Z

I'd like to suggest the following change:

Get rid of oleaccProxyWow64.reg
Use either sysroot\regedit.exe or syswow64\regedit.exe based on architecture, with the same registry patch, just like with regsvr32

There is also regedt32.exe, that resides in system32 or syswow64 respectively.

michaelDCurran · 2018-03-29T22:16:31Z

I'm happy to make this change purely to get rid of a reg file, but do you believe there is any functional advantage for doing this? My understanding is that the 32 bit version of regedit will write directly into the wow6432node subtree automatically, thus I think you are correct that we don't need the second file.

derekriemer · 2018-04-03T12:18:11Z

source/setup.py

@@ -114,7 +114,7 @@ def run(self):



Update copyright headers while here?

LeonarddeR · 2018-04-03T12:56:00Z

@michaelDCurran commented on 30 mrt. 2018 00:16 CEST:

I'm happy to make this change purely to get rid of a reg file, but do
you believe there is any functional advantage for doing this?

Not really, though an advantage might be that we can ensure for these patches or possibly added patches in the future that they do exactly the same thing. It would need to be tested, though.

My understanding is that the 32 bit version of regedit will write
directly into the wow6432node subtree automatically, thus I think you
are correct that we don't need the second file.

Looks like we have the same understanding here.

Do you actually know what this patch is supposed to do on Windows 10 for ARM? Is there something like wow64 there?

* Update copyright in setup.py * Use the same reg file for registering oleacc proxy for both 64 and 32 bit, but just use a different version of regedit.exe for each.

cary-rowen · 2021-04-14T06:23:09Z

This feature seems to be disabled at this time. Can you investigate this?
@michaelDCurran

cary-rowen · 2021-04-14T06:27:08Z

The discussion about the problem is included on groups.io, using this PR can not solve the problem, but manually performing the steps in #2807 can successfully solve the problem
https://nvda.groups.io/g/nvda/topic/nvda_doesn_t_read_context/82006419?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,82006419

michaelDCurran added 3 commits March 8, 2018 09:41

Installer: re-register some common COM interfaces which commonly get …

8793a65

…broken by bad uninstallers.

COMRegistrationFixes tool: add a backslash to the systemDrive. Also d…

d3a9795

…eremove some unused functions.

Add the COM Registrations Fixing tool to NVDA's Tools menu.

3a5abd7

michaelDCurran requested a review from feerrenrut March 12, 2018 02:41

Add a warning dialog to the COM Registration Fixing tool when run man…

e1d7978

…ually from the Tools menu.

feerrenrut approved these changes Mar 12, 2018

View reviewed changes

LeonarddeR reviewed Mar 12, 2018

View reviewed changes

michaelDCurran added 2 commits March 12, 2018 17:44

Add copyright header

7c2e945

Add a module docstring

877362b

michaelDCurran added a commit that referenced this pull request Mar 12, 2018

Incubates #8075

e550d32

nvaccessAuto added the incubating label Mar 12, 2018

nvaccessAuto assigned michaelDCurran Mar 12, 2018

LeonarddeR mentioned this pull request Mar 16, 2018

An error occurs during update of NVDA "next" snapshots #8089

Closed

LeonarddeR mentioned this pull request Mar 23, 2018

NVDA Fails to recognise pop-up menus, tree views and other controls after installation of Microsoft Office #5415

Closed

Regedit is in c:\windows not c:\windows\system32.

b5c71e4

This happened to still work on x64 as there is a 32 bit copy of regedit in c:\windows\syswow64, and as NVDA itself is 32 bit it always found it. Fixes #8089

michaelDCurran added a commit that referenced this pull request Mar 28, 2018

Incubates #8075

1ce0745

michaelDCurran added a commit that referenced this pull request Mar 28, 2018

Incubates #8075

4f44a46

derekriemer reviewed Apr 3, 2018

View reviewed changes

source/setup.py

@@ -114,7 +114,7 @@ def run(self):

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Update copyright headers while here?

Address revew comments:

7aefc2b

* Update copyright in setup.py * Use the same reg file for registering oleacc proxy for both 64 and 32 bit, but just use a different version of regedit.exe for each.

michaelDCurran added a commit that referenced this pull request Apr 5, 2018

Incubates #8075

355d3da

michaelDCurran merged commit ba77168 into master Apr 20, 2018

nvaccessAuto removed the incubating label Apr 20, 2018

nvaccessAuto added this to the 2018.2 milestone Apr 20, 2018

Adriani90 mentioned this pull request Jan 31, 2020

Adjusted the bug report slightly and added two more simple questions which should be considered before submiting an issue #10720

Merged

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Provide a tool to re-register particular COM interfaces that may become unregistered or broken by uninstallers, breaking platform accessibility #8075

Provide a tool to re-register particular COM interfaces that may become unregistered or broken by uninstallers, breaking platform accessibility #8075

michaelDCurran commented Mar 12, 2018

LeonarddeR commented Mar 12, 2018

michaelDCurran commented Mar 12, 2018 via email

jcsteh commented Mar 12, 2018

feerrenrut Mar 12, 2018

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michaelDCurran Mar 12, 2018

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LeonarddeR Mar 12, 2018

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Brian1Gaff commented Mar 16, 2018 via email

Qchristensen commented Mar 16, 2018

LeonarddeR commented Mar 17, 2018

Qchristensen commented Mar 17, 2018

LeonarddeR commented Mar 29, 2018

michaelDCurran commented Mar 29, 2018 via email

derekriemer Apr 3, 2018

LeonarddeR commented Apr 3, 2018

cary-rowen commented Apr 14, 2021

cary-rowen commented Apr 14, 2021

Provide a tool to re-register particular COM interfaces that may become unregistered or broken by uninstallers, breaking platform accessibility #8075

Provide a tool to re-register particular COM interfaces that may become unregistered or broken by uninstallers, breaking platform accessibility #8075

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michaelDCurran commented Mar 12, 2018

Link to issue number:

Summary of the issue:

Description of how this pull request fixes the issue:

Testing performed:

Known issues with pull request:

Change log entry:

LeonarddeR commented Mar 12, 2018

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jcsteh commented Mar 12, 2018

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Brian1Gaff commented Mar 16, 2018 via email

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