Fix #204. #211
Merged
Fix #204. #211
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
The DFA handles word boundaries by tagging each state with an `is_word` flag that lets us determine whether the next byte in the haystack should cause a word boundary instruction to match. We were mishandling how this tagging happened for start states. In particular, the tag was not used as an index into the start state cache, and therefore could wind up choosing an incorrect but previously computed start state with the wrong flags set. This leads to incorrect matches. We fix this by using the right flags to generate an index.
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Outdated suggestions cannot be applied.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.
The DFA handles word boundaries by tagging each state with an
is_wordflag that lets us determine whether the next byte in the haystack should
cause a word boundary instruction to match. We were mishandling how this
tagging happened for start states. In particular, the tag was not used as
an index into the start state cache, and therefore could wind up choosing
an incorrect but previously computed start state with the wrong flags set.
This leads to incorrect matches.
We fix this by using the right flags to generate an index.