Python 3.8/gettext: replace custom pgettext implementation with built--in pgettext #12109
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…ccess#9207. As gettext.pgettext is present, there is no need to manually assign NVDA's own pgettext function to built-in namespace for add-ons. Therefore remove this assignment.
…vaccess#9207. As Python 3.8 includes gettext.pgettext, there is no need for NVDA's implementation of pgettext function. Therefore remove makePgettext and builtins namespace assignment from language handler.
…vaccess#9207. As Python 3.8 includes gettext.pgettext, add it to built-in namespace by using 'names' parameter of translation.install method.
|
Hi, Note that this change may affect add-ons. As far as I know, all add-ons hosted on community add-ons website are not affected. Thanks. |
|
Hi You write:
In this case, a point should be added in the changes for developpers describing what is the impact on add-ons. Thanks. |
|
Hi, the impact has to do with localizations, no changes to function calls and such. Thanks.
|
|
Have you tested that with this change `pgettext`` works correctly when used for translatable strings in add-ons? |
…. Re nvaccess#9207." This reverts commit 991de43 so add-on translations will work.
|
Hi, yes. The needed change is assigning Python’s pgettext function to add-on namespace (done in the upcoming commit). To answer another question, no it will not require changes to add-ons at all. Thanks.
|
…hon's pgettext function. Re nvaccess#9207. Add-on initialization will still require assigning pgettext to add-on namespace, therefore use translations.pgettext instead of now removed NVDA-specific implementation.
michaelDCurran
approved these changes
Mar 11, 2021
7 tasks
michaelDCurran
added a commit
that referenced
this pull request
Apr 20, 2021
Fixes #12152 Fixes #12154 Since upgrading to Python 3.8, several serious crashes in NVDA have been reported. Specifically: • NVDA crashing when using the SAPI4 speech synthesizer: #12152 • NVDA crashing when using Windows Explorer on Windows Server 2012: #12154 Both of these issues were traced to stack corruption after a Python callback of NVDA's was called from external libraries. In SAPI4's case, after calling NVDA's implementation of ITTSBufNotifySink::TextDataStarted, and in the Windows Server 2012 case: IUIAutomationPropertyChangedEventHandler::handlePropertyChangedEvent. It seems as though libFFI / Python ctypes is not cleaning the stack properly after executing a Python callback with the stdcall calling convention (ctypes WINFUNCTYPE), where the callback contained at least one argument larger than 4 bytes (E.g. a long long, or a VARIANT struct), and the arguments preceding it were such that this argument was not aligned to an 8 byte boundary. E.g. the callback might be: • callback(void*, long long) or • callback(void*, void*, int, VARIANT) See Python bug: https://bugs.python.org/issue38748 On that bug I have attached a minimal testcase. This bug affects both Python 3.8 and Python 3.9. The bug is most likely in the libFFI project used by Python's ctypes module. Python 3.8 switched to a much more recent and official version of libFFI I believe. Although we do really want to move to Python 3.8+ as soon as we can, right now this bug makes it impossible to do so. We could specifically work around the currently known manifestations by moving some of that code into C++, but that brings its own risks, and we still don't know where else this issue may appear in our code. The appropriate thing to do right now is stay on Python 3.7 until we can work with Python / libFFI to get this resolved. Description of how this pull request fixes the issue: Downgrades to Python 3.7 by referencing Python 3.7 (rather than 3.8) in NVDA's build system. The existing PRs that needed to be reverted were: • Updating brlAPI to a Python 3.8 build: nvaccess/nvda-misc-deps#20 • Switching to using Python's own pgettext: #12109 • calling os.add_dll_directory when loading liblouis: #12020 None of these PRs provided any user visible changes. The rest of the Python 3.8 work, including the switch to a virtual environment etc is all compatible with Python 3.7 and can remain.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Hi,
This will impact localization and resolves a long-standing issue with it:
Link to issue number:
Closes #9207
Summary of the issue:
Python 3.8 introduces gettext.pgettext to obtain translated text based on context. Prior to this, NVDA defined a custom implementation of pgettext function.
Description of how this pull request fixes the issue:
Replace custom pgettext implementation and built-in namespace assignment with Python 3.8's gettext.pgettext by using translation.install function's "names" sequence parameter.
Testing strategy:
Two ways:
Known issues with pull request:
None
Change log entry:
None needed, unless a note to developers is needed to highlight pgettext function.
Code Review Checklist:
This checklist is a reminder of things commonly forgotten in a new PR.
Authors, please do a self-review and confirm you have considered the following items.
Mark items you have considered by checking them.
You can do this when editing the Pull request description with an x:
[ ]becomes[x].You can also check the checkboxes after the PR is created.