net/http: content type detection does not work correctly for some documents that start with HTML comments #25771

guliyevemil1 · 2018-06-07T03:45:16Z

Some website documents start with "".

None of these cases are detected correctly because "<!--" htmlSig is treated like a regular HTML tag when in reality behaves slightly differently.

What version of Go are you using (`go version`)?

❯ go version
go version go1.10.2 darwin/amd64

Does this issue reproduce with the latest release?

Yes.

What operating system and processor architecture are you using (`go env`)?

❯ go env
GOARCH="amd64"
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"

What did you do?

package main

import (
	"fmt"
	"net/http"
)

func main() {
	fmt.Println(http.DetectContentType([]byte(`<!--[if !IE]> This has been served from cache <![endif]--><html><body>Hello,world</body></html>`)))
	fmt.Println(http.DetectContentType([]byte(`<!-- [if !IE]> This has been served from cache <![endif]--><html><body>Hello,world</body></html>`)))
}

https://play.golang.org/p/f6-N3OA9FGU

What did you expect to see?

text/html; charset=utf-8
text/html; charset=utf-8

What did you see instead?

text/plain; charset=utf-8
text/html; charset=utf-8

agnivade · 2018-06-07T04:16:22Z

We follow the algorithm laid out at http://mimesniff.spec.whatwg.org/. According to it, the string <!-- must be followed by a tag-terminating byte. A tag terminating byte is either a space or closing angle bracket.

So this is working as intended. If you want this changed, I would suggest raising an issue at https://github.com/whatwg/mimesniff.

guliyevemil1 changed the title ~~net/http: content type detection does not work correctly for HTML comments~~ net/http: content type detection does not work correctly for some documents that start with HTML comments Jun 7, 2018

gopherbot added the Documentation label Jun 7, 2018

agnivade closed this Jun 7, 2018

golang locked and limited conversation to collaborators Jun 7, 2019

gopherbot added the FrozenDueToAge label Jun 7, 2019

golang / go

net/http: content type detection does not work correctly for some documents that start with HTML comments #25771

net/http: content type detection does not work correctly for some documents that start with HTML comments #25771

guliyevemil1 commented Jun 7, 2018 •

edited

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agnivade commented Jun 7, 2018

golang / go

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net/http: content type detection does not work correctly for some documents that start with HTML comments #25771

net/http: content type detection does not work correctly for some documents that start with HTML comments #25771

Comments

guliyevemil1 commented Jun 7, 2018 • edited

What version of Go are you using (go version)?

Does this issue reproduce with the latest release?

What operating system and processor architecture are you using (go env)?

What did you do?

What did you expect to see?

What did you see instead?

This comment has been minimized.

agnivade commented Jun 7, 2018

guliyevemil1 commented Jun 7, 2018 •

edited

What version of Go are you using (`go version`)?

What operating system and processor architecture are you using (`go env`)?