From 1f042830391494f4ad48036359d2788bf0527dba Mon Sep 17 00:00:00 2001
From: Arun Isaac
Date: Sat, 5 Dec 2020 19:33:52 +0530
Subject: email: Do not capture cfws in atoms and dot-atoms.

* email/email.scm (define-atom-pattern): Do not capture cfws unless
specified.
(atom): Do not specify cfws.
(define-dot-atom-pattern): Do not capture cfws.
(define-word-pattern): New macro.
(cfws-captured-atom, cfws-captured-word): New patterns.
(obs-phrase): Use cfws-captured-word.
(received-token): Capture all.
(parse-mime-entity): Post process received and received-token.
* tests/email.scm ("parse email headers"): Fix test.
---
 email/email.scm | 40 ++++++++++++++++++++++++++++++----------
 1 file changed, 30 insertions(+), 10 deletions(-)

(limited to 'email/email.scm')

diff --git a/email/email.scm b/email/email.scm
index 56c1b57..398ddb3 100644
--- a/email/email.scm
+++ b/email/email.scm
@@ -168,18 +168,23 @@
 (define-printable-ascii-character-pattern atext
   "\"" "(" ")" "," "." ":" ";" "<" ">" "@" "[" "\\" "]")
 
-(define-syntax-rule (define-atom-pattern name cfws)
-  (define-peg-pattern name body
-    (and (? cfws) (+ atext) (? cfws))))
+(define-syntax define-atom-pattern
+  (syntax-rules ()
+    ((define-atom-pattern name)
+     (define-peg-pattern name body
+       (and (ignore (? cfws)) (+ atext) (ignore (? cfws)))))
+    ((define-atom-pattern name cfws)
+     (define-peg-pattern name body
+       (and (? cfws) (+ atext) (? cfws))))))
 
-(define-atom-pattern atom cfws)
+(define-atom-pattern atom)
 
 (define-peg-pattern dot-atom-text body
   (and (+ atext) (* (and "." (+ atext)))))
 
 (define-syntax-rule (define-dot-atom-pattern name cfws)
   (define-peg-pattern name body
-    (and (? cfws) dot-atom-text (? cfws))))
+    (and (ignore (? cfws)) dot-atom-text (ignore (? cfws)))))
 
 (define-dot-atom-pattern dot-atom cfws)
 
@@ -203,11 +208,21 @@
 
 ;;; Miscellaneous tokens
 
-(define-peg-pattern word body
-  (or atom quoted-string))
+;; According to RFC5322§3.2.3, the leading and trailing cfws in atom
+;; are semantically not part of it, and should be ignored. But, to
+;; support obs-phrase, we need to capture it. Hence, we define a set
+;; of cfws-captured-* patterns needed by obs-phrase.
+
+(define-syntax-rule (define-word-pattern name atom)
+  (define-peg-pattern name body
+    (or atom quoted-string)))
+
+(define-word-pattern word atom)
+(define-atom-pattern cfws-captured-atom cfws)
+(define-word-pattern cfws-captured-word cfws-captured-atom)
 
 (define-peg-pattern obs-phrase body
-  (and word (* (or word "." cfws))))
+  (and cfws-captured-word (* (or "." cfws word))))
 
 ;; We set phrase to be the same as obs-phrase since, according to
 ;; their definitions in RFC5322, all phrases are obs-phrases.
@@ -526,7 +541,7 @@
 ;;; Trace fields
 
 ;; word is given last priority in the ordered choice
-(define-peg-pattern received-token body
+(define-peg-pattern received-token all
   (or angle-addr addr-spec domain word))
 
 (define-field-pattern received "Received"
@@ -988,7 +1003,12 @@ list of header keys and values."
   (pre-post-order
    (peg:tree
     (match-pattern fields headers))
-   `((date-time . ,(lambda node
+   `((received . ,(match-lambda*
+                    (`(received ,tokens ,timestamp)
+                     (list 'received (string-join tokens) timestamp))))
+     (received-token . ,(match-lambda*
+                          (`(received-token ,token) token)))
+     (date-time . ,(lambda node
                      (match-let
                          ((`((day ,day) (month ,month) (year ,year)
                              (hours ,hours) (minutes ,minutes) (seconds ,seconds) (zone . ,zone))
-- 
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