Fix a bug in elisp--xref-find-definitions related to cl-generic defaults

* lisp/progmodes/elisp-mode.el (elisp--xref-find-definitions): Fix bug
with cl-generic defaults.
(elisp--xref-find-references): Add doc string.

* test/automated/elisp-mode-tests.el (xref-elisp-generic-*): Improve
tests to find bug.

3 files changed, 36 insertions, 28 deletions

diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index 735e08eb324..edfb045a795 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -2421,11 +2421,13 @@ the file, which in some cases may cause a security hole.
   This section describes low-level subroutines for completing a file
 name.  For higher level functions, see @ref{Reading File Names}.
 
-@defun file-name-all-completions partial-filename directory
-This function returns a list of all possible completions for a file
-whose name starts with @var{partial-filename} in directory
-@var{directory}.  The order of the completions is the order of the files
-in the directory, which is unpredictable and conveys no useful
+@defun file-name-all-completions partial-filename directory &optional predicate
+This function returns a list of all possible completions for a file in
+directory @var{directory} whose name starts with
+@var{partial-filename} and for which @var{predicate} (called with the
+filename) returns non-nil. If @var{predicate} is nil (the default), it
+is ignored. The order of the completions is the order of the files in
+the directory, which is unpredictable and conveys no useful
 information.
 
 The argument @var{partial-filename} must be a file name containing no
diff --git a/lisp/progmodes/elisp-mode.el b/lisp/progmodes/elisp-mode.el
index 8afae150a1d..7614bacf1bb 100644
--- a/lisp/progmodes/elisp-mode.el
+++ b/lisp/progmodes/elisp-mode.el
@@ -720,10 +720,15 @@ non-nil result supercedes the xrefs produced by
               (dolist (method (cl--generic-method-table generic))
                 (let* ((info (cl--generic-method-info method));; qual-string combined-args doconly
                        (specializers (cl--generic-method-specializers method))
+                       (non-default nil)
                        (met-name (cons symbol specializers))
                        (file (find-lisp-object-file-name met-name 'cl-defmethod)))
+                  (dolist (item specializers)
+                    ;; default method has all 't' in specializers
+                    (setq non-default (or non-default (not (equal t item)))))
+
                   (when (and file
-                             (or specializers   ;; default method has null specializers
+                             (or non-default
                                  (nth 2 info))) ;; assuming only co-located default has null doc string
                     (if specializers
                         (let ((summary (format elisp--xref-format-extra 'cl-defmethod symbol (nth 1 info))))
@@ -800,6 +805,7 @@ non-nil result supercedes the xrefs produced by
 (declare-function project-current "project")
 
 (defun elisp--xref-find-references (symbol)
+  "Find all references to SYMBOL (a string) in the current project."
   (cl-mapcan
    (lambda (dir)
      (xref-collect-references symbol dir))
diff --git a/test/automated/elisp-mode-tests.el b/test/automated/elisp-mode-tests.el
index 7886b557141..2f6675a2804 100644
--- a/test/automated/elisp-mode-tests.el
+++ b/test/automated/elisp-mode-tests.el
@@ -258,7 +258,7 @@ to (xref-elisp-test-descr-to-target xref)."
 (cl-defstruct (xref-elisp-root-type)
   slot-1)
 
-(cl-defgeneric xref-elisp-generic-no-methods ()
+(cl-defgeneric xref-elisp-generic-no-methods (arg1 arg2)
   "doc string generic no-methods"
   ;; No default implementation, no methods, but fboundp is true for
   ;; this symbol; it calls cl-no-applicable-method
@@ -269,44 +269,44 @@ to (xref-elisp-test-descr-to-target xref)."
 ;; causes the batch mode test to fail; the symbol shows up as
 ;; ‘this’. It passes in interactive tests, so I haven't been able to
 ;; track down the problem.
-(cl-defmethod xref-elisp-generic-no-default ((this xref-elisp-root-type))
+(cl-defmethod xref-elisp-generic-no-default ((this xref-elisp-root-type) arg2)
   "doc string generic no-default xref-elisp-root-type"
   "non-default for no-default")
 
 ;; defgeneric after defmethod in file to ensure the fallback search
 ;; method of just looking for the function name will fail.
-(cl-defgeneric xref-elisp-generic-no-default ()
+(cl-defgeneric xref-elisp-generic-no-default (arg1 arg2)
   "doc string generic no-default generic"
   ;; No default implementation; this function calls the cl-generic
   ;; dispatching code.
   )
 
-(cl-defgeneric xref-elisp-generic-co-located-default ()
+(cl-defgeneric xref-elisp-generic-co-located-default (arg1 arg2)
   "doc string generic co-located-default"
   "co-located default")
 
-(cl-defmethod xref-elisp-generic-co-located-default ((this xref-elisp-root-type))
+(cl-defmethod xref-elisp-generic-co-located-default ((this xref-elisp-root-type) arg2)
   "doc string generic co-located-default xref-elisp-root-type"
   "non-default for co-located-default")
 
-(cl-defgeneric xref-elisp-generic-separate-default ()
+(cl-defgeneric xref-elisp-generic-separate-default (arg1 arg2)
   "doc string generic separate-default"
   ;; default implementation provided separately
   )
 
-(cl-defmethod xref-elisp-generic-separate-default ()
+(cl-defmethod xref-elisp-generic-separate-default (arg1 arg2)
   "doc string generic separate-default default"
   "separate default")
 
-(cl-defmethod xref-elisp-generic-separate-default ((this xref-elisp-root-type))
+(cl-defmethod xref-elisp-generic-separate-default ((this xref-elisp-root-type) arg2)
   "doc string generic separate-default xref-elisp-root-type"
   "non-default for separate-default")
 
-(cl-defmethod xref-elisp-generic-implicit-generic ()
+(cl-defmethod xref-elisp-generic-implicit-generic (arg1 arg2)
   "doc string generic implicit-generic default"
   "default for implicit generic")
 
-(cl-defmethod xref-elisp-generic-implicit-generic ((this xref-elisp-root-type))
+(cl-defmethod xref-elisp-generic-implicit-generic ((this xref-elisp-root-type) arg2)
   "doc string generic implicit-generic xref-elisp-root-type"
   "non-default for implicit generic")
 
@@ -327,9 +327,9 @@ to (xref-elisp-test-descr-to-target xref)."
               (xref-make-elisp-location
                'xref-elisp-generic-no-default 'cl-defgeneric
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
-   (xref-make "(cl-defmethod xref-elisp-generic-no-default ((this xref-elisp-root-type)))"
+   (xref-make "(cl-defmethod xref-elisp-generic-no-default ((this xref-elisp-root-type) arg2))"
               (xref-make-elisp-location
-               '(xref-elisp-generic-no-default xref-elisp-root-type) 'cl-defmethod
+               '(xref-elisp-generic-no-default xref-elisp-root-type t) 'cl-defmethod
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
    ))
 
@@ -340,9 +340,9 @@ to (xref-elisp-test-descr-to-target xref)."
               (xref-make-elisp-location
                'xref-elisp-generic-co-located-default 'cl-defgeneric
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
-   (xref-make "(cl-defmethod xref-elisp-generic-co-located-default ((this xref-elisp-root-type)))"
+   (xref-make "(cl-defmethod xref-elisp-generic-co-located-default ((this xref-elisp-root-type) arg2))"
               (xref-make-elisp-location
-               '(xref-elisp-generic-co-located-default xref-elisp-root-type) 'cl-defmethod
+               '(xref-elisp-generic-co-located-default xref-elisp-root-type t) 'cl-defmethod
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
    ))
 
@@ -353,26 +353,26 @@ to (xref-elisp-test-descr-to-target xref)."
               (xref-make-elisp-location
                'xref-elisp-generic-separate-default 'cl-defgeneric
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
-   (xref-make "(cl-defmethod xref-elisp-generic-separate-default ())"
+   (xref-make "(cl-defmethod xref-elisp-generic-separate-default (arg1 arg2))"
               (xref-make-elisp-location
-               '(xref-elisp-generic-separate-default) 'cl-defmethod
+               '(xref-elisp-generic-separate-default t t) 'cl-defmethod
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
-   (xref-make "(cl-defmethod xref-elisp-generic-separate-default ((this xref-elisp-root-type)))"
+   (xref-make "(cl-defmethod xref-elisp-generic-separate-default ((this xref-elisp-root-type) arg2))"
               (xref-make-elisp-location
-               '(xref-elisp-generic-separate-default xref-elisp-root-type) 'cl-defmethod
+               '(xref-elisp-generic-separate-default xref-elisp-root-type t) 'cl-defmethod
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
    ))
 
 (xref-elisp-deftest find-defs-defgeneric-implicit-generic
   (elisp--xref-find-definitions 'xref-elisp-generic-implicit-generic)
   (list
-   (xref-make "(cl-defmethod xref-elisp-generic-implicit-generic ())"
+   (xref-make "(cl-defmethod xref-elisp-generic-implicit-generic (arg1 arg2))"
               (xref-make-elisp-location
-               '(xref-elisp-generic-implicit-generic) 'cl-defmethod
+               '(xref-elisp-generic-implicit-generic t t) 'cl-defmethod
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
-   (xref-make "(cl-defmethod xref-elisp-generic-implicit-generic ((this xref-elisp-root-type)))"
+   (xref-make "(cl-defmethod xref-elisp-generic-implicit-generic ((this xref-elisp-root-type) arg2))"
               (xref-make-elisp-location
-               '(xref-elisp-generic-implicit-generic xref-elisp-root-type) 'cl-defmethod
+               '(xref-elisp-generic-implicit-generic xref-elisp-root-type t) 'cl-defmethod
                (expand-file-name "elisp-mode-tests.el" emacs-test-dir)))
    ))