Add checking if both strings are the same in `SequenceMatcher.find_longest_match`

Feature or enhancement

Proposal:

Add checking if sequences a[alo:ahi] and b[blo:bhi] are the same on the beginning of the method find_longest_match in SequenceMatcher. For identical sequences there is no reason to run whole logic when simple check can be done. It appears to fix issue when comparing two slightly different strings ends up with waiting forever for the result. This solves problem reported here https://github.com/pytest-dev/pytest/issues/8998

Proposed fix:

if a[alo:ahi] == b[blo:bhi]:
    return Match(alo, blo, len(a[alo:ahi]))

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-132167

Commencez par SequenceMatcher.find_longest_match et examinez comment il gère la comparaison de séquences demandée. Consultez le rapport pytest lié concernant le blocage, puis ajoutez une couverture ciblée pour des chaînes identiques et légèrement différentes ; le travail est terminé lorsque l’optimisation fonctionne sans modifier le match renvoyé.