From 6c29d71f456bb0fc6e2f33a3b8e7caacae0a6bb0 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Sat, 3 Jun 2017 14:12:20 -0700
Subject: [PATCH] more

---
 pitfall/binparser/gif-parse.rkt |  6 ++++++
 pitfall/binparser/main.rkt      | 29 ++++++++++++++++-------------
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/pitfall/binparser/gif-parse.rkt b/pitfall/binparser/gif-parse.rkt
index 1c9eb15d..f7fe95fd 100644
--- a/pitfall/binparser/gif-parse.rkt
+++ b/pitfall/binparser/gif-parse.rkt
@@ -29,3 +29,9 @@
                       (make-hasheq (list (cons 'logical-screen-descriptor '(162 162 (#f #t #f #f #f #t #f #t) 0 0))
                                          '(signature . "GIF")
                                          '(version . "87a")))))
+
+
+(define-rule bad-bitfield (:bitfield [reserved (:bits 3)]
+                                     [disposal (:bits 3 #:type integer?)]))
+
+(bad-bitfield (bad-bitfield (open-input-bytes #"A")))
\ No newline at end of file
diff --git a/pitfall/binparser/main.rkt b/pitfall/binparser/main.rkt
index c8ed278c..9ad7dd86 100644
--- a/pitfall/binparser/main.rkt
+++ b/pitfall/binparser/main.rkt
@@ -158,7 +158,10 @@
 (define-seq-style-rule :bitfield bitfield-inner)
 
 (define (bitfield-inner #:type [type list?] . rule-procs)
-  ((make-inner-proc (λ (xs) (bitfield->bytes (append* xs))) 'bitfield) type rule-procs))
+  ((make-inner-proc (λ (xs) (let ([bf (append* xs)])
+                              (unless (zero? (modulo (length bf) 8))
+                                (raise-result-error ':bitfield (format "total field length is multiple of 8, got length ~a" (length bf)) bf))
+                              (bitfield->bytes bf))) 'bitfield) type rule-procs))
 
 (define-seq-style-rule :seq seq-inner)
 
@@ -170,18 +173,18 @@
     (procedure-rename
      (λ (x) (define-values (input-proc output-proc output-check)
               (case-proc type
-                [hash?
-                 (define rule-proc-names (resolve-duplicates (map procedure-name rule-procs)))
-                 (values (curry list->hash-with-keys rule-proc-names)
-                         (curry hash->list-with-keys rule-proc-names)
-                         (λ (x)
-                           (unless (and (hash? x) (hash-has-keys? x rule-proc-names))
-                             (raise (binary-problem (format "hash with ~a keys, namely ~a" (length rule-procs) rule-proc-names) x)))))]
-                [list? (values identity identity
-                              (λ (x)
-                                (unless (and (list? x) (= (length rule-procs) (length x)))
-                                  (raise (binary-problem (format "list of ~a values" (length rule-procs)) x)))))]
-                [else (raise-argument-error sym "not a supported type" type)]))
+                         [hash?
+                          (define rule-proc-names (resolve-duplicates (map procedure-name rule-procs)))
+                          (values (curry list->hash-with-keys rule-proc-names)
+                                  (curry hash->list-with-keys rule-proc-names)
+                                  (λ (x)
+                                    (unless (and (hash? x) (hash-has-keys? x rule-proc-names))
+                                      (raise (binary-problem (format "hash with ~a keys, namely ~a" (length rule-procs) rule-proc-names) x)))))]
+                         [list? (values identity identity
+                                        (λ (x)
+                                          (unless (and (list? x) (= (length rule-procs) (length x)))
+                                            (raise (binary-problem (format "list of ~a values" (length rule-procs)) x)))))]
+                         [else (raise-argument-error sym "not a supported type" type)]))
        (match x
          [(? input-port? p) (input-proc (map (λ (rule-proc) (rule-proc p)) rule-procs))]
          [else