Default argument for find-library

2 files changed, 20 insertions, 5 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index ebd92a40033..7aa77756e45 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2007-10-31  Sean O'Rourke  <sorourke@cs.ucsd.edu>
+
+        * emacs-lisp/find-func.el (find-library): use library at
+        point as default interactive argument.
+
 2007-10-31  Juanma Barranquero  <lekktu@gmail.com>
 
         * emacs-lisp/elp.el (elp-report-limit, elp-restore-all)
diff --git a/lisp/emacs-lisp/find-func.el b/lisp/emacs-lisp/find-func.el
index 6a259ffd4f7..ede196721ae 100644
--- a/lisp/emacs-lisp/find-func.el
+++ b/lisp/emacs-lisp/find-func.el
@@ -194,11 +194,21 @@ TYPE should be nil to find a function, or `defvar' to find a variable."
 (defun find-library (library)
   "Find the elisp source of LIBRARY."
   (interactive
-   (list
-    (completing-read "Library name: "
-                     'locate-file-completion
-                     (cons (or find-function-source-path load-path)
-                           (find-library-suffixes)))))
+   (let* ((path (cons (or find-function-source-path load-path)
+                      (find-library-suffixes)))
+          (def (if (eq (function-called-at-point) 'require)
+                   (save-excursion
+                     (backward-up-list)
+                     (forward-char)
+                     (backward-sexp -2)
+                     (thing-at-point 'symbol))
+                 (thing-at-point 'symbol))))
+     (when def
+       (setq def (and (locate-file-completion def path 'test) def)))
+     (list
+      (completing-read (if def (format "Library name (default %s): " def)
+                         "Library name: ")
+                       'locate-file-completion path nil nil nil def))))
   (let ((buf (find-file-noselect (find-library-name library))))
     (condition-case nil (switch-to-buffer buf) (error (pop-to-buffer buf)))))