Hello, This is a request for keeping some current behavior only under some option, which will default to nil, i.e. will say not to behave as has been the case so far.
When an error is created by some conditions triggering a \PackageError in original LaTeX support files, such as package sources, or sometimes more obscure support files, Emacs/AUCTeX opens this file in a buffer. Very rarely is this useful, even to hardcore LaTeX developers. And it is dangerous when the LaTeX installation was not done under restricted file permissions, as then one can by mistake modify in place the said file. And sometimes one has some package installed under $HOME for various reasons where most likely user has write permission on the file so the danger of overwriting something is high then. I have very very often been confronted with that and never ever was it useful, even though I do LaTeX macro programming. Knowing the filename originating the \PackageError would be almost always largely sufficient. This becomes even more problematic when Debug Warnings is activated, because Warnings tend to be emitted very often by packages, sometimes for not so urgent reasons, so here the risks are increased. Regarding errors, going to the source line of the error is definitely a good thing (more than that, it is crucial to AUCTeX usefulness) *when* limited to going to *current* document. LaTeX Package Errors have a definite pattern (hmm... make this plural due to LaTeX3, see for example what happens when one attempts to compile via pdflatex a document using fontspec -- which I know AUCTeX guards against, usually) and it should be feasible to distinguish between a deliberate \PackageError and a core TeX error. Presumably this is what AUCTeX knows already to do, and anyhow the simplest could be to keep current code but by default add to it a check whether the-file-where-lies-the-offending-error is in current directory and display it only then, except if some customizable option "always-go-to-error-originating-file" has been made use of. Best, Jean-François
