changing valid char to XML 1.1 rather than 1.0 and reverting changes from recent PR

pkgs/racket-pkgs/racket-doc/xml/xml.scrbl

@@ -110,7 +110,7 @@ Represents an attribute within an element.}
  If @racket[(permissive-xexprs)] is @racket[#t], then equivalent to @racket[any/c], otherwise equivalent to @racket[(make-none/c 'permissive)]}
 
 @defproc[(valid-char? [x any/c]) boolean?]{
- Returns true if @racket[x] is an exact-nonnegative-integer whose character interpretation under UTF-8 is from the set (#x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]), in accordance with section 2.2 of the XML 1.1 spec.
+ Returns true if @racket[x] is an exact-nonnegative-integer whose character interpretation under UTF-8 is from the set ([#x1-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]), in accordance with section 2.2 of the XML 1.1 spec.
 }
 
 @defstruct[(entity source) ([text (or/c symbol? valid-char?)])]{

pkgs/racket-pkgs/racket-test/tests/xml/test.rkt

@@ -563,9 +563,8 @@ END
                            "<root>&nbsp;</root>")      
        (test-xexpr->string '(root () 40)
                            "<root>&#40;</root>")
-       (check-exn
+       (test-xexpr->string '(root () "\f")
-        exn:fail?
+                           "<root>\f</root>")
-        (λ () (xexpr->string "\f")))
        ; XXX more xexpr->string tests
        )
       
@@ -639,7 +638,7 @@ END
          (test-validate-xexpr '(a ([href "#"]) "string"))
          
          (test-validate-xexpr/exn #f #f)
-         (test-validate-xexpr/exn 4 4)
+         (test-validate-xexpr 4)
          (test-validate-xexpr/exn + +)
          (test-validate-xexpr/exn '(a ([href foo]) bar) 'foo)
          (test-validate-xexpr/exn '("foo" bar) '("foo" bar))

racket/collects/xml/private/core.rkt

@@ -25,12 +25,9 @@
 (define-struct (cdata source) (string) #:transparent)
 
 ; Section 2.2 of XML 1.1
-; (XML 1.0 is slightly different and looks less restrictive)
+; (XML 1.0 is slightly different and more restrictive)
 (define (valid-char? i)
   (and (exact-nonnegative-integer? i)
-       (or (= i #x9)
+       (or (<= #x1     i #xD7FF)
-           (= i #xA)
+           (<= #xE000  i #xFFFD)
-           (= i #xD)
-           (<= #x20 i #xD7FF)
-           (<= #xE000 i #xFFFD)
            (<= #x10000 i #x10FFFF))))

racket/collects/xml/private/writer.rkt

@@ -154,7 +154,7 @@
   (let ([n (entity-text entity)])
     (fprintf out (if (number? n) "&#~a;" "&~a;") n)))
 
-(define escape-table #px"[<>&[:cntrl:]]")
+(define escape-table #px"[<>&]")
 (define escape-attribute-table #rx"[<>&\"]")
 
 (define (replace-escaped s)
@@ -164,18 +164,12 @@
     [(#\>) "&gt;"]
     [(#\&) "&amp;"]
     [(#\") "&quot;"]
-    [(#\newline) "\n"]
+    [else c]))
-    [else
-     (define i (char->integer c))
-     (if (valid-char? i)
-       (format "&#~a;" i)
-       (error 'escape "illegal character, ~v" c))]))
 
 ;; escape : String -> String
 (define (escape x table)
   (regexp-replace* table x replace-escaped))
 
-
 ;; write-string/excape: String Regexp Output-Port -> Void
 ;; Writes the string to the output port, with a fast-path 
 ;; that tries to avoid using string escapes unless necessary.
@@ -185,7 +179,6 @@
         [else
          (write-string str out)]))
 
-
 (provide escape
          write-string/escape
          escape-table