Salvage fallback buffer from burning house

src/App.h

@@ -192,6 +192,9 @@ public:
                 /* Move any backpressure */
                 std::string backpressure(std::move(((AsyncSocketData<SSL> *) res->getHttpResponseData())->buffer));
 
+                /* Keep any fallback buffer alive until we returned from open event, keeping req valid */
+                std::string fallback(std::move(res->getHttpResponseData()->salvageFallbackBuffer()));
+
                 /* Destroy HttpResponseData */
                 res->getHttpResponseData()->~HttpResponseData();
 

src/HttpParser.h

@@ -221,6 +221,11 @@ private:
 
 public:
 
+    /* We do this to prolong the validity of parsed headers by keeping only the fallback buffer alive */
+    std::string &&salvageFallbackBuffer() {
+        return std::move(fallback);
+    }
+
     void *consumePostPadded(char *data, int length, void *user, fu2::unique_function<void *(void *, HttpRequest *)> &&requestHandler, fu2::unique_function<void *(void *, std::string_view, bool)> &&dataHandler, fu2::unique_function<void *(void *)> &&errorHandler) {
 
         HttpRequest req;