Avoid crash in Chrome by no longer fetching currently selected item in listboxes#9458
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…xes in Chrome. as this can cause Chrome to crash.
feerrenrut
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feerrenrut
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The issue in Chrome was resolved in version 77. It is now safe to re-enable fetching of selected items for listboxes. Original issue #9364 And original fix - For RC: #9458 - For Master: #9430 Chrome bug tracker: https://crbug.com/947898
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Link to issue number:
Fixes #9364
Summary of the issue:
When using Google Chrome with NVDA 2019.1, Chrome can crash when the user interacts with certain listboxes. The crash is in Chrome's IEnumVARIANT::next, when fetched from IAccessible::accSelection.
NVDA calls this to render the currently selected item in a listbox into its virtualBuffer.
This code was introduced in #9166.
It is unclear as to the exact situation that causes this crash, as not all listboxes seem to crash necessarily. An issue has been filed with Google, but until the crash is addressed in Chrome stable, we should avoid it completely by not trying to fetch the selection at all in Chrome, which was what we did in NVDA 2018.4 and below.
This code has already been diabled for particular listboxes in Chrome due to other bugs, so we should just disable it for all of them for now.
Description of how this pull request fixes the issue:
This PR stops NVDA from fetching and rendering the currently selected item in listboxes, specifically in Google Chrome. Causing NVDA to exhibit the same behaviour it did in 2018.4.
Testing performed:
Tested with the steps in #9364 to ensure that Chrome no longer crashes.
Ensured that in Mozilla Gecko browsers we still render the currently ssleected item in listboxes, using tests in #9166.
Known issues with pull request:
This approach may be a little boarder than it should be, but until we completely understand the cause from Google's side, this is the safest option.
Change log entry:
Bug fixes: