Unbreak jumping to an alias's definition

* lisp/emacs-lisp/find-func.el (find-function-library): Return a pair
(ORIG-FUNCTION . LIBRARY) instead of just its second element.
(find-function-noselect): Use it.

* lisp/progmodes/elisp-mode.el (elisp--xref-identifier-file): Rename to
`elisp--xref-identifier-location', incorporate logic from
`elisp--xref-find-definitions', use the changed
`find-function-library' return value.

1 files changed, 17 insertions, 11 deletions

diff --git a/lisp/emacs-lisp/find-func.el b/lisp/emacs-lisp/find-func.el
index e1586a96716..3131be09eb1 100644
--- a/lisp/emacs-lisp/find-func.el
+++ b/lisp/emacs-lisp/find-func.el
@@ -312,9 +312,14 @@ The search is done in the source for library LIBRARY."
 	      (cons (current-buffer) nil))))))))
 
 (defun find-function-library (function &optional lisp-only verbose)
-  "Return the library FUNCTION is defined in.
+  "Return the pair (ORIG-FUNCTION . LIBRARY) for FUNCTION.
 
-If FUNCTION is a built-in function and LISP-ONLY is non-nil,
+ORIG-FUNCTION is the original name, after removing all advice and
+resolving aliases.  LIBRARY is an absolute file name, a relative
+file name inside the C sources directory, or a name of an
+autoloaded feature.
+
+If ORIG-FUNCTION is a built-in function and LISP-ONLY is non-nil,
 signal an error.
 
 If VERBOSE is non-nil, and FUNCTION is an alias, display a
@@ -336,13 +341,14 @@ message about the whole chain of aliases."
             def (symbol-function (find-function-advised-original function))))
     (if aliases
         (message "%s" aliases))
-    (cond
-     ((autoloadp def) (nth 1 def))
-     ((subrp def)
-      (if lisp-only
-          (error "%s is a built-in function" function))
-      (help-C-file-name def 'subr))
-     ((symbol-file function 'defun)))))
+    (cons function
+          (cond
+           ((autoloadp def) (nth 1 def))
+           ((subrp def)
+            (if lisp-only
+                (error "%s is a built-in function" function))
+            (help-C-file-name def 'subr))
+           ((symbol-file function 'defun))))))
 
 ;;;###autoload
 (defun find-function-noselect (function &optional lisp-only)
@@ -362,8 +368,8 @@ searched for in `find-function-source-path' if non-nil, otherwise
 in `load-path'."
   (if (not function)
     (error "You didn't specify a function"))
-  (let ((library (find-function-library function lisp-only t)))
-    (find-function-search-for-symbol function nil library)))
+  (let ((func-lib (find-function-library function lisp-only t)))
+    (find-function-search-for-symbol (car func-lib) nil (cdr func-lib))))
 
 (defun find-function-read (&optional type)
   "Read and return an interned symbol, defaulting to the one near point.