MFC: Apply arch= selection to the qandatoc mode. This fixes

link generation with no actual target.

Reported by:	Tim Witthoeft (tim.witthoeft at gmail.com)

release/doc/share/sgml/release.dsl

@@ -54,7 +54,6 @@
      ((equal? STR (car s)) #t)
      (else (loop (cdr s))))))
 
-; Deal with conditional inclusion of text via entities.
 (default
   (let* ((arch (attribute-string (normalize "arch")))
 	 (role (attribute-string (normalize "role")))
@@ -97,6 +96,49 @@
      ; None of the above
      (else (empty-sosofo)))))
 
+(mode qandatoc
+  (default
+  (let* ((arch (attribute-string (normalize "arch")))
+	 (role (attribute-string (normalize "role")))
+	 (for-arch (entity-text "arch")))
+    (cond
+
+     ; If role=historic, and we're not printing historic things, then
+     ; don't output this element.
+     ((and (equal? role "historic")
+	   (not %include-historic%))
+      (empty-sosofo))
+      
+
+     ; If arch= not specified, then print unconditionally.  This clause
+     ; handles the majority of cases.
+     ((or (equal? arch #f) (equal? arch ""))
+      (next-match))
+
+     ; arch= specified, see if it's equal to "all".  If so, then
+     ; print unconditionally.  Note that this clause could be
+     ; combined with the check to see if arch= wasn't specified
+     ; or was empty; they have the same outcome.
+     ((equal? arch "all")
+      (next-match))
+
+     ; arch= specified.  If we're building for all architectures,
+     ; then print it prepended with the set of architectures to which
+     ; this element applies.
+     ;
+     ; XXX This doesn't work.
+;     ((equal? for-arch "all")
+;      (sosofo-append (literal "[") (literal arch) (literal "] ")
+;		     (process-children)))
+
+     ; arch= specified, so we need to check to see if the specified
+     ; parameter includes the architecture we're building for.
+     ((string-list-match? for-arch (split-string-to-list arch))
+      (next-match))
+
+     ; None of the above
+     (else (empty-sosofo))))))
+
 ; We might have some sect1 level elements where the modification times
 ; are significant.  An example of this is the "What's New" section in
 ; the release notes.  We enable the printing of pubdate entry in