fix a bug in plugin Redirector.

[tanglong3bf]

#include <drogon/drogon.h>
#include <drogon/plugins/Redirector.h>

int main()
{
    drogon::app().addListener("0.0.0.0", 8000);
    // {"plugins": [{"name": "drogon::plugin::Redirector"}]}
    drogon::app().loadConfigFile("../config.json");
    drogon::app().registerBeginningAdvice([] {
        drogon::plugin::Redirector *redirector =
            drogon::app().getPlugin<drogon::plugin::Redirector>();

        redirector->registerRedirectHandler(
            [](const drogon::HttpRequestPtr &req,
               std::string &protocol,
               std::string &host,
               bool &pathChanged) -> bool {
                if (req->path() == "/")
                {
                    protocol = "https://";
                    host = "github.com";
                    req->setPath("/drogonframework/drogon");
                    pathChanged = true;
                }
                return true;
            });

        redirector->registerPathRewriteHandler(
            [](const drogon::HttpRequestPtr &req) -> bool {
                if (!req->path().starts_with("/api") && req->path() != "/")
                {
                    req->setPath("/");
                    return true;
                }
                return false;
            });
    });
    drogon::app().run();
    return 0;
}

For the above code, the expected goal is: access localhost:8000, redirect to https://github.com/drogonframework/drogon. The old version of the Redirector plugin redirects to the github.com homepage, because the loop of pathRewriteHandlers_ modifies the path. This is not as expected.

[Mis1eader-dev]

Will try to give it a review once I'm back home (╯°□°)╯︵ ┻━┻

P.S. the emoticon is just for fun

[Mis1eader-dev]

The reason this happens is

[](const drogon::HttpRequestPtr &req) -> bool {
                if (!req->path().starts_with("/api") && req->path() != "/")
                {
                    req->setPath("/");
                    return true;
                }
                return false;
            }

Triggers right after the redirect logic populates protocol, host, and new path to GitHub.

Hence your check ends up overwriting the path to "/".

I'm unsure of the consequences of changing the orders, it may break other plugins in the process.

I'll do further tests and confirm. Or we could just add another handler to the pipeline and call it a day lol