fix broken-link reporting by `scribble'

original commit: 853e47f05e6feaaa4d29662d2b5a2042a2bea30a

collects/scribble/base-render.rkt

@@ -236,9 +236,19 @@
     (define/public (get-defined ci)
       (hash-map (collect-info-ht ci) (lambda (k v) k)))
 
-    (define/public (get-undefined ri)
+    (define/public (get-external ri)
       (hash-map (resolve-info-undef ri) (lambda (k v) k)))
 
+    (define/public (get-undefined ri)
+      (for/list ([(k v) (in-hash (resolve-info-undef ri))]
+                 #:unless (or (eq? v 'found)
+                              (and v
+                                   ;; v is a search key; see if any key in the set was resolved:
+                                   (let ([ht (hash-ref (resolve-info-searches ri) v)])
+                                     (for/or ([k2 (in-hash-keys ht)])
+                                       (eq? 'found (hash-ref (resolve-info-undef ri) k2 #f)))))))
+        k))
+
     (define/public (transfer-info ci src-ci)
       (let ([in-ht (collect-info-ext-ht ci)])
         (for ([(k v) (collect-info-ext-ht src-ci)])

collects/scribble/core.rkt

@@ -39,13 +39,20 @@
                  #t)]))))
 
 (define (resolve-get/ext? part ri key)
+  (resolve-get/ext?* part ri key #f))
+
+(define (resolve-get/ext?* part ri key search-key)
   (let-values ([(v ext?) (resolve-get/where part ri key)])
     (when ext?
-      (hash-set! (resolve-info-undef ri) (tag-key key ri) #t))
+      (hash-set! (resolve-info-undef ri) (tag-key key ri) 
+                 (if v 'found search-key)))
     (values v ext?)))
 
 (define (resolve-get part ri key)
-  (let-values ([(v ext?) (resolve-get/ext? part ri key)])
+  (resolve-get* part ri key #f))
+
+(define (resolve-get* part ri key search-key)
+  (let-values ([(v ext?) (resolve-get/ext?* part ri key search-key)])
     v))
 
 (define (resolve-get/tentative part ri key)
@@ -61,14 +68,12 @@
                                        search-key s-ht)
                             s-ht)))])
     (hash-set! s-ht key #t))
-  (resolve-get part ri key))
+  (resolve-get* part ri key search-key))
 
 (define (resolve-get-keys part ri key-pred)
-  (let ([l null])
-    (hash-for-each
-     (collected-info-info (part-collected-info part ri))
-     (lambda (k v) (when (key-pred k) (set! l (cons k l)))))
-    l))
+  (for/list ([k (in-hash-keys (collected-info-info (part-collected-info part ri)))]
+             #:when (key-pred k))
+    k))
 
 (provide (struct-out collect-info)
          (struct-out resolve-info))

collects/scribblings/scribble/renderer.scrbl

@@ -187,6 +187,7 @@ object.}
 
 Serializes the collected info in @racket[ri].}
 
+
 @defmethod[(deserialize-info [v any/c]
                              [ci collect-info?]
                              [#:root root-path (or/c path-string? false/c) #f])
@@ -199,6 +200,32 @@ recorded in @racket[ci] as relative to an instantiation-supplied
 @racket[root-path] are deserialized as relative instead to the given
 @racket[root-path].}
 
+
+@defmethod[(get-defined [ci collect-info?]) (listof tag?)]{
+
+Returns a list of tags that were defined within the documents
+represented by @racket[ci].}
+
+
+@defmethod[(get-external [ri resolve-info?]) (listof tag?)]{
+
+Returns a list of tags that were referenced but not defined within the
+documents represented by @racket[ri] (though possibly found in
+cross-reference information transferred to @racket[ri] via
+@racket[xref-transfer-info]).}
+
+
+@defmethod[(get-undefined [ri resolve-info?]) (listof tag?)]{
+
+Returns a list of tags that were referenced by the resolved documents
+with no target found either in the resolved documents represented by
+@racket[ri] or cross-reference information transferred to @racket[ri]
+via @racket[xref-transfer-info].
+
+If multiple tags were referenced via @racket[resolve-search] and a
+target was found for any of the tags using the same dependency key,
+then no tag in the set is included in the list of undefined tags.}
+
 }
 
 @; ----------------------------------------