(error-data): Delete functionscratch/error-API

Remove `error-data` from the new error API: it is not really
compatible with a more abstract view of error descriptors, and
in practice it seems to be used only in two ways (both of them rare):

- To add some contextual info to an error.  We should maybe add
  a dedicated support for that, but it's not clear what shape it
  should take, ideally (there was a discussion about with Alan
  and myself in emacs-devel a few years ago).
- To do some other massaging whose correctness is dubious anyway.

* doc/lispref/control.texi (Handling Errors): Remove `error-data`.

* lisp/epa-file.el (epa-file--find-file-not-found-function): Don't use
`error-data`.
(epa-file--error-add-context): New function, extracted from
`epa-file-insert-file-contents`.
(epa-file-insert-file-contents): Use it instead of `error-data`.

* lisp/subr.el (error-data): Delete function.

1 files changed, 0 insertions, 4 deletions

diff --git a/doc/lispref/control.texi b/doc/lispref/control.texi
index 3925bdd1b40..d3662f727cc 100644
--- a/doc/lispref/control.texi
+++ b/doc/lispref/control.texi
@@ -2483,10 +2483,6 @@ to @code{condition-case} whose error condition you want to re-throw.
 This function returns the error symbol of the error descriptor @var{error}.
 @end defun
 
-@defun error-data error
-This function returns the data of the error descriptor @var{error}.
-@end defun
-
 @defun error-slot-value error pos
 This function returns the value in the field number @var{pos} of the error
 descriptor @var{error}.  The fields are numbered starting with 1.  E.g.,