(help-make-xrefs): Don't make hyperlinks for incorrect coding systems.

diff --git a/lisp/help.el b/lisp/help.el
index a6d804c3e6ecece6543ab9551859a9ae3407d6b7..a5d9bb22f579fbcf4031f6c7dde481b402e3e7f7 100644 (file)
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -1134,7 +1134,7 @@ that."
                             (sym (intern-soft data)))
                        (cond
                         ((match-string 3) ; coding system
-                         (and (coding-system-p sym)
+                         (and sym (coding-system-p sym)
                               (help-xref-button
                                5 #'describe-coding-system sym
                                "mouse-2, RET: describe this coding system")))
@@ -1143,7 +1143,7 @@ that."
                               (help-xref-button
                                5 #'describe-input-method data
                                "mouse-2, RET: describe this input method")))
-                        ((coding-system-p sym)
+                        ((and sym (coding-system-p sym))
                          (help-xref-button
                           5 #'describe-coding-system sym
                           "mouse-2, RET: describe this coding system"))