Make describe-variable look up the variable in the current buffer

* lisp/help-fns.el (describe-variable): Get the variable
definition in the buffer we were called from (in case it only
exists there) (bug#21252).

1 files changed, 16 insertions, 10 deletions

diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index e2cb9f82a1b..e17586c28fe 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -699,17 +699,23 @@ it is displayed along with the global value."
   (interactive
    (let ((v (variable-at-point))
          (enable-recursive-minibuffers t)
+         (orig-buffer (current-buffer))
          val)
-     (setq val (completing-read (if (symbolp v)
-                                    (format
-                                     "Describe variable (default %s): " v)
-                                  "Describe variable: ")
-                                obarray
-                                (lambda (vv)
-                                  (or (get vv 'variable-documentation)
-                                      (and (boundp vv) (not (keywordp vv)))))
-                                t nil nil
-                                (if (symbolp v) (symbol-name v))))
+     (setq val (completing-read
+                (if (symbolp v)
+                    (format
+                     "Describe variable (default %s): " v)
+                  "Describe variable: ")
+                obarray
+                (lambda (vv)
+                  ;; In case the variable only exists in the buffer
+                  ;; the command we switch back to that buffer before
+                  ;; we examine the variable.
+                  (with-current-buffer orig-buffer
+                    (or (get vv 'variable-documentation)
+                        (and (boundp vv) (not (keywordp vv))))))
+                t nil nil
+                (if (symbolp v) (symbol-name v))))
      (list (if (equal val "")
                v (intern val)))))
   (let (file-name)