Fold repeated header lines per RFC 7230 §3.2.2

http.carp

@@ -183,15 +183,27 @@ the type yourself, instead you can [parse](#parse) it.")
       (the (Maybe String) (Maybe.Nothing))
       hdrs)))
 
+(private header-values)
+(hidden header-values)
+(defn header-values [hdrs name]
+  (let [lower-name &(String.ascii-to-lower name)]
+    (Map.kv-reduce
+      &(fn [acc k v]
+        (if (= &(String.ascii-to-lower k) lower-name)
+          (Array.concat &[acc @v])
+          acc))
+      (the (Array String) [])
+      hdrs)))
+
 (private transfer-encoding-chunked?)
 (hidden transfer-encoding-chunked?)
 (defn transfer-encoding-chunked? [hdrs]
-  (match (header-lookup hdrs "transfer-encoding")
-    (Maybe.Just v)
+  (Array.any?
+    &(fn [v]
       (Array.any?
         &(fn [tok] (= &(String.trim tok) "chunked"))
-        &(String.split-by &(String.ascii-to-lower &v) &[\,]))
-    (Maybe.Nothing) false))
+        &(String.split-by &(String.ascii-to-lower v) &[\,])))
+    &(header-values hdrs "transfer-encoding")))
 
 (doc Request "is a request data type. It holds the `verb` of the request, the
 `version`, the `uri`, the `cookies`, the `headers`, and the `body`.")
@@ -1317,6 +1329,7 @@ server's `offers`, honoring the request's `Accept` header (RFC 7231 §5.3.2). A
 request with no `Accept` header accepts anything. See
 [`Accept.negotiate`](#negotiate).")
   (defn negotiate [r offers]
-    (match (Request.header r "Accept")
-      (Maybe.Nothing) (Accept.negotiate "" offers)
-      (Maybe.Just a) (Accept.negotiate &a offers))))
+    (let [accepts (header-values (headers r) "Accept")]
+      (if (Array.empty? &accepts)
+        (Accept.negotiate "" offers)
+        (Accept.negotiate &(String.join ", " &accepts) offers)))))

test/http.carp

@@ -67,6 +67,14 @@
     (match (Request.negotiate &r offers)
       (Maybe.Just m) m
       (Maybe.Nothing) @"NONE")))
+
+(defn req-parse-pick [s offers]
+  (match (Request.parse s)
+    (Result.Success r)
+      (match (Request.negotiate &r offers)
+        (Maybe.Just m) m
+        (Maybe.Nothing) @"NONE")
+    _ @"PARSE-FAIL"))
 ; ---- chunked transfer-encoding test helpers ----
 (defn dechunk-ok [s]
   (match (TransferEncoding.dechunk s) (Result.Success b) b _ @"FAIL"))
@@ -807,6 +815,20 @@
     "text/html"
     &(req-pick-noaccept &[@"text/html" @"application/json"])
     "Request.negotiate with no Accept header accepts anything")
+  (assert-equal test
+    "application/json"
+    &(req-parse-pick &multi-header &[@"application/json"])
+    "Request.negotiate folds an Accept split across multiple lines")
+  (assert-equal test
+    "text/html"
+    &(req-parse-pick &multi-header &[@"text/html" @"application/json"])
+    "Request.negotiate still honors the first line of a multi-line Accept")
+  (assert-equal test
+    "text/html"
+    &(req-parse-pick
+      "GET / HTTP/1.1\r\nHost: localhost\r\nAccept: text/html\r\n\r\n"
+      &[@"text/html"])
+    "Request.negotiate honors a single-line Accept")
   (assert-equal test
     &(dechunk-ok "4\r\nWiki\r\n5\r\npedia\r\n0\r\n\r\n")
     "Wikipedia"
@@ -887,6 +909,21 @@
     (req-chunked? "POST / HTTP/1.1\r\nTransfer-Encoding: chunked\r\n\r\n")
     "Request.chunked? true for Transfer-Encoding: chunked")
 
+  (assert-true test
+    (req-chunked?
+      "POST / HTTP/1.1\r\nTransfer-Encoding: gzip\r\nTransfer-Encoding: chunked\r\n\r\n")
+    "Request.chunked? true when chunked is on a second Transfer-Encoding line")
+
+  (assert-true test
+    (req-chunked?
+      "POST / HTTP/1.1\r\nTransfer-Encoding: gzip\r\ntransfer-encoding: chunked\r\n\r\n")
+    "Request.chunked? folds Transfer-Encoding lines that differ only in case")
+
+  (assert-false test
+    (req-chunked?
+      "POST / HTTP/1.1\r\nTransfer-Encoding: gzip\r\nTransfer-Encoding: deflate\r\n\r\n")
+    "Request.chunked? false when no Transfer-Encoding line lists chunked")
+
   ; ---- Cache-Control ----
   (assert-equal test
     3600