Link to issue number:

Fixes #8980

Summary of the issue:

NvDA's browseMode quick navigation in virtualBuffers uses regular expressions to match on a node's attributes to locate the next valid item.
However, in certain scenarios, Firefox can seem to freeze when quick navigating by landmarks, if the extendedAria add-on in installed and reportArticles is enabled.
Technically:
In Firefox at least, it seems that the c++ regex_match function can throw a regex_error exception if the input string is too long. For instance, if searching for landmarks (including articles) and it comes upon an article node with an aria-label with a length greater than 294 characters.

Description of how this pull request fixes the issue:

1. We now catch regex_error thrown by regex_match, log a debug warning, and return false (I.e. pretend the regex did not match). This in itself stops the freeze, but does mean that a possible article will be skipped.
2. We limit the length of attribute value strings added to re regular expression input to 100 characters. Currently this is for all attribute values, as matchAttributes is really supposed to be agnostic to what attributes it is dealing with. Though we could specifically hardcode a check for 'name'. I can't however really think of a situation where any attribute value needs to be more than 100 characters for matching purposes. We could instead also up the limit to say 256, or in deed 294, but I have a feeling this may not be universal across machines.

Testing performed:

Tested the original testcases in #8980. The correct articles were found, and no freeze occured.

Known issues with pull request:

None.

Change log entry:

Bug fixes:

• Fixed a freeze in Firefox sometimes seen when qquick navigating by landmarks, if the extendedAria add-on is in use. (Freeze when navigating by landmarks with certain labeled article landmarks #8980)