Hydrolysis under basic conditions
I find the top mechanism unlikely for two reasons.

1) In the top mechanism, the proton removed in the first step should be way less acidic than a typical hydroxyl since the intermediate is already negatively charged. Going to a di-anion should be very far uphill, and therefore, slow. If that di-anion was ever formed, the next step would be exceedingly fast

2) In the bottom mechanism, the first step should be fast. It's intramolecular and entropically favored. The second step is instantaneous.

I can't imagine any text book includes the top mechanism. Check your book for saponification of esters.