redirect_canonical() should strip trailing protocols

[onlyonemj]

I was crawling some of my sites as I was setting up SEO strategies and found really odd 301 redirects on all tested sites.

1. ​https://domain.com/http:// redirects to ​https://domain.com/http:/ (one forward slash less). So it's basically a nonexistent page redirecting to another nonexistent page

2. To figure what could be causing this I needed to check if this was happening to just this site or others. I discovered that all sites suffered the same issue regardless of host or webserver stack.

3. Wondering if Cloudflare a common plugin was causing it, I unproxied and entered all the sites in dev mode and had all plugins disabled and the problem still persists

Spiders/crawlers pick this up - appending ​http:// to end of root URLs manually is not required.

This issue persists - likely a bug in WordPress redirect API. Anybody care to replicate and confirm? Is this a bug?

[SergeyBiryukov]

Hi there, welcome to WordPress Trac! Thanks for the report.

Replying to onlyonemj:

This issue persists - likely a bug in WordPress redirect API. Anybody care to replicate and confirm? Is this a bug?

Yes, this appears to be an issue with the redirect_canonical() function, which strips multiple slashes from URL​, but doesn't handle a case like this. It seems stripping http:// completely would be the expected behavior here.

[onlyonemj]

Thanks for replying @SergeyBiryukov, not a hardcore coder but the multiple slashes link you gave looks like it strips extraneous forward slashes at the end of URLs which is expected behaviour in the case of folder paths. It doesn't address whether if WP is responsible for creating the http: prepend to the forward slashes? Is WordPress creating those or are the crawlers wrong? One crawler detects it but Screaming Frog isn't. The ​http:// page appending right after root does not exist anywhere nor was ever created.

[donmhico]

@onlyonemj - Thanks for the ticket. I'm having trouble finding out where in WP Core is http:// is being appended in the URL.

While it's possible to add a logic in redirect_canonical() which strips out http:// at the end of the URL but I feel like that won't be tackling the source of the problem.

Did you try disabling the Cloudflare plugin since you mentioned its a common plugin. Also try checking your sitemaps if https://domain.com/http:// is there.