FUEL: when browsing vocab documentation, use the fuel-help--buffer-link variable to determine what vocabulary we are "in"

misc/fuel/fuel-help.el

@@ -343,9 +343,15 @@ With prefix, the current page is deleted from history."
 
 ;;; IN: support
 
+(defun fuel-help--find-in-buffer-link ()
+  (when (and fuel-help--buffer-link
+             (equal (nth 2 fuel-help--buffer-link) 'vocab))
+    (car fuel-help--buffer-link)))
+
 (defun fuel-help--find-in ()
   (save-excursion
     (or (factor-find-in)
+        (fuel-help--find-in-buffer-link)
         (and (goto-char (point-min))
              (re-search-forward "Vocabulary: \\(.+\\)$" nil t)
              (match-string-no-properties 1)))))

misc/fuel/fuel-tests.el

@@ -20,6 +20,7 @@
 (add-to-list 'load-path (file-name-directory load-file-name))
 
 (require 'ert)
+(require 'fuel-help)
 (require 'fuel-markup)
 
 ;; fuel-markup
@@ -33,3 +34,19 @@
                (fuel-markup--quotation quot)
                (buffer-string))
              "a quotation with stack effect ( args kw -- ret )"))))
+
+;; fuel-help
+(ert-deftest find-in-w/vocabulary ()
+  (should (equal
+           (with-temp-buffer
+             (insert "Vocabulary: imap")
+             (fuel-help--find-in))
+           "imap")))
+
+(ert-deftest find-in-w/buffer-link ()
+  (should (equal
+           (with-temp-buffer
+             (setq fuel-help--buffer-link '("foob" "foob" vocab))
+             (insert "Help page contents")
+             (fuel-help--find-in))
+           "foob")))