From 99d577f43a1788378a51af3753a99d8729f59706 Mon Sep 17 00:00:00 2001
From: King_DuckZ <king_duckz@gmx.com>
Date: Thu, 3 Sep 2020 00:55:16 +0100
Subject: [PATCH] Bugfix in HttpResponse

string_views are potentially wrong if raw is very small
and stdlib has small string optimisation. Use unique_ptr
instead to force allocations in all cases.
---
 src/nap/http_response.hpp |  4 ++--
 src/nap/page_fetch.cpp    | 40 ++++++++++++++++++++++++++++++++-------
 2 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/src/nap/http_response.hpp b/src/nap/http_response.hpp
index 3859ab6..4db8b81 100644
--- a/src/nap/http_response.hpp
+++ b/src/nap/http_response.hpp
@@ -17,7 +17,7 @@
 
 #pragma once
 
-#include <string>
+#include <memory>
 #include <string_view>
 #include <vector>
 #include <utility>
@@ -25,7 +25,7 @@
 namespace nap {
 
 struct HttpResponse {
-	std::string raw;
+	std::unique_ptr<char[]> raw;
 	std::vector<std::pair<std::string_view, std::string_view>> header;
 	std::string_view body;
 	std::string_view http_ver;
diff --git a/src/nap/page_fetch.cpp b/src/nap/page_fetch.cpp
index 34118b0..e2fc270 100644
--- a/src/nap/page_fetch.cpp
+++ b/src/nap/page_fetch.cpp
@@ -24,6 +24,7 @@
 #include <sstream>
 #include <algorithm>
 #include <cassert>
+#include <tuple>
 
 namespace nap {
 namespace {
@@ -35,6 +36,29 @@ namespace {
 
 		return std::equal(protocol, protocol + protocolLen, parUrl.begin());
 	}
+
+	std::tuple<std::unique_ptr<char[]>, std::string_view, std::string_view> make_raw_string (
+		const std::ostringstream& head,
+		const std::ostringstream& body
+	) {
+		//TODO: use .view() with c++20
+		auto head_str = head.str();
+		auto body_str = body.str();
+
+		const std::size_t size = head_str.size() + 1 + body_str.size();
+		auto ret = std::make_unique<char[]>(size);
+
+		std::copy(head_str.begin(), head_str.end(), ret.get());
+		ret[head_str.size()] = '\n';
+		std::copy(body_str.begin(), body_str.end(), ret.get() + head_str.size() + 1);
+
+		const char* const buff = ret.get();
+		return std::make_tuple(
+			std::move(ret),
+			std::string_view(buff, head_str.size()),
+			std::string_view(buff + head_str.size() + 1, body_str.size())
+		);
+	}
 } //unnamed namespace
 
 HttpResponse page_fetch (
@@ -73,14 +97,16 @@ HttpResponse page_fetch (
 
 	HttpResponse resp;
 	resp.code = easy.get_info<CURLINFO_RESPONSE_CODE>().get();
-	resp.raw = header_oss.str();
-	resp.raw += "\n";
-	const std::size_t body_start = resp.raw.size();
-	resp.raw += body_oss.str();
-	std::string_view raw_view(resp.raw);
-	resp.body = raw_view.substr(body_start);
 
-	auto parsed_header = header_parse(raw_view.substr(0, body_start));
+	std::string_view head;
+	{
+		auto [raw, head_tmp, body] = make_raw_string(header_oss, body_oss);
+		head = head_tmp;
+		resp.raw = std::move(raw);
+		resp.body = body;
+	}
+
+	auto parsed_header = header_parse(head);
 	resp.header = std::move(parsed_header.fields);
 	assert(resp.code == parsed_header.code);
 	resp.http_ver = parsed_header.version;