bug#26837: Wrong file in "autoloading failed to define" error

[Alex]

Glenn Morris <rgm@gnu.org> writes:

> In 58326f0 I check if the car is nil (though I don't see how it could be).
> Could add the same thing to eval.c.

According to the docstring of load-history:

 As an exception, one of the alist elements may have FILE-NAME nil,
 for symbols and features not associated with any file.

With your proposed patch I don't think it's really an issue anymore, but
previously it could have triggered a segfault under that rare condition.

> I don't know if it should be mentioned explicitly.

If the intention is that someone can expect the position of files in
load-history to be updated so that it provides a history of some sort
(i.e. use (caar load-history) to get the last file evaluated), then I
would think that there should be a line mentioning it somewhere.