apply patch add-content-type maintained by other RICs (#212)

Author: bmoffatt

include/aws/http/response.h

@@ -38,6 +38,7 @@ class response {
     inline void set_response_code(aws::http::response_code c);
     inline void set_content_type(char const* ct);
     inline std::string const& get_body() const;
+    inline std::string const& get_content_type() const;
 
 private:
     response_code m_response_code;
@@ -139,6 +140,12 @@ inline std::string const& response::get_body() const
 {
     return m_body;
 }
+
+inline std::string const& response::get_content_type() const
+{
+    return m_content_type;
+}
+
 inline void response::add_header(std::string name, std::string const& value)
 {
     std::transform(name.begin(), name.end(), name.begin(), ::tolower);

include/aws/lambda-runtime/runtime.h

@@ -56,6 +56,11 @@ struct invocation_request {
      */
     std::string function_arn;
 
+    /**
+     * The Content-type of the current invocation.
+     */
+    std::string content_type;
+
     /**
      * Function execution deadline counted in milliseconds since the Unix epoch.
      */

src/runtime.cpp

@@ -281,6 +281,7 @@ runtime::next_outcome runtime::get_next()
     invocation_request req;
     req.payload = resp.get_body();
     req.request_id = std::move(out).get_result();
+    req.content_type = resp.get_content_type();
 
     out = resp.get_header(TRACE_ID_HEADER);
     if (out.is_success()) {