Fix Request Cookies When Receiving Multiple

Previously, when parsing the "Cookie" header for an HTTP request, the header
was parsed as if it was the "Set-Cookie" header of an HTTP response. As a
result, the CookieJar object of a Request object would never contain more than
a single cookie, with any additional cookies being stored in Cookie.ext of the
first cookie. This commit fixes this issue by implementing a
CookieJar.addFromRaw method which adds multiple Cookies to a CookieJar from a
string. HeadersStep::apply now uses CookieJar.addFromRaw instead of
Cookie::fromRaw.

include/pistache/cookie.h

@@ -78,6 +78,7 @@ class CookieJar {
     CookieJar();
 
     void add(const Cookie& cookie);
+    void addFromRaw(const char *str, size_t len);
     Cookie get(const std::string& name) const;
 
     bool has(const std::string& name) const;

src/common/cookie.cc

@@ -210,6 +210,34 @@ CookieJar::add(const Cookie& cookie) {
     cookies.insert(std::make_pair(cookie.name, cookie));
 }
 
+void
+CookieJar::addFromRaw(const char *str, size_t len) {
+	RawStreamBuf<> buf(const_cast<char *>(str), len);
+	StreamCursor cursor(&buf);
+
+	while (!cursor.eof()) {
+		StreamCursor::Token nameToken(cursor);
+
+		if (!match_until('=', cursor))
+			throw std::runtime_error("Invalid cookie, missing value");
+
+		auto name = nameToken.text();
+
+		if (!cursor.advance(1))
+			throw std::runtime_error("Invalid cookie, missing value");
+
+		StreamCursor::Token valueToken(cursor);
+
+		match_until(';', cursor);
+		auto value = valueToken.text();
+
+		Cookie cookie(std::move(name), std::move(value));
+		add(cookie);
+
+		cursor.advance(2);
+	}
+}	
+
 Cookie
 CookieJar::get(const std::string& name) const {
     auto it = cookies.find(name);

src/common/http.cc

@@ -294,9 +294,7 @@ namespace Private {
             }
 
             if (name == "Cookie") {
-                message->cookies_.add(
-                        Cookie::fromRaw(cursor.offset(start), cursor.diff(start))
-                );
+		message->cookies_.addFromRaw(cursor.offset(start), cursor.diff(start));
             }
 
             else if (Header::Registry::isRegistered(name)) {