Fix TokensList::getPrevious which was not able to reach very first token

[Tithugues]

This change aims to fix a bug in the TokensList::getPrivious method which was not able to reach the very first token. As you can see in the test case, the method returned null before returning the SELECT token.

If it was not a bug, but an expected behavior, please let me know.

Maybe such a bugfix should be backported to 5.7 as well, but I can't find a maintenance branch for this version.

Thank you.

[williamdes]

Do you have a SQL statement that could create a regression test for us ?

Maybe such a bugfix should be backported to 5.7 as well, but I can't find a maintenance branch for this version.

That's okay, 5.8 will replace 5.7 without any breaking changes. Like previous versions :)

[Tithugues]

Do you have a SQL statement that could create a regression test for us ?

I think that there already is one. The one used in the test class starts by SELECT, but as we can see in the test itself, when we are on index 2 (the * of the SELECT), then getting previous token again lead to null, whereas it should have lead to the SELECT token.

Is it clear enough? Does it make sense to you?

That's okay, 5.8 will replace 5.7 without any breaking changes. Like previous versions :)

Thanks! I hope it will be released soon then. 🙏