bug#18342: 24.3.93; jumping to compilation error location gives the wrong column

[Stefan Monnier]

> Regarding `compilation-error-regexp-alist', the
> `compilation-first-column' probably could be there, but then it should
> be something like `compilation-compiler-var-alist' instead :)

I tend to agree that the "first-column" info should probably be placed
alongside the regexp (same for compilation-error-screen-columns, BTW).

> There are unclear cases e.g. with maven: what if we use Oracle JDK which
> outputs columns beginning with 0 and then change to another JDK which
> outputs beginning with 1?  Would maven correct it's output?  I doubt so.
> Then we should have two items in the alist: maven-oracle and maven-smth.

Indeed, there are "hard" cases.  Luckily, column positions usually
aren't so terribly important, so being off by a few chars is annoying
but bearable.


        Stefan