HTTP Body io.Reader as parser input results in ErrUnexpectedEndOfDemo

[martig3]

Describe the bug
Passing an HTTP Body io.Reader to NewParser() then calling ParseToEnd() results in an demo stream ended unexpectedly (ErrUnexpectedEndOfDemo) error

To Reproduce
I tested with https://www.dropbox.com/s/7lb1r11olhc6a1b/2021-6-6_pug_de_overpass_60bc5197ffc453a0de48212d.dem?dl=0 but I believe this is reproducible with all demos.

Code:

package main

import (
	"github.com/gin-gonic/gin"
	"github.com/markus-wa/demoinfocs-golang/v2/pkg/demoinfocs"
)

func main() {
	r := gin.Default()
	r.POST("/parse-stats", func(c *gin.Context) {
		p := demoinfocs.NewParser(c.Request.Body)
		err := p.ParseToEnd()
		if err != nil {
			c.AbortWithStatusJSON(500, err.Error())
			return
		}
               c.JSON(200, "success")
	})
	err := r.Run()
	if err != nil {
		println(err)
		return
	} // listen and serve on 0.0.0.0:8080
}

Expected behavior
Demo gets parsed successfully as it does with os.Open() readers. Specifically from the code example, POSTing to /parse-stats should return a 200 and not panic on p.ParseToEnd().

Library version
v2.9.0

[markus-wa]

Thanks for raising this, I will probably need to fix something in https://github.com/markus-wa/gobitread 😅

[markus-wa]

ah, for anyone else who finds this (as discussed via gitter):
the workaround for now is to use io.ReadAll() and then creating a bytes.NewReader() on top of the returned byte array

[markus-wa]

sorry this took so long @martig3 , would you be able to try with this branch: #305

go get -u github.com/markus-wa/demoinfocs-golang/v2@fix-bitread-streaming

I'm not 100% sure it will fix every case but for me I had a similar issue with gzip that went away with the change.
Would be great if you can test it with Gin as I don't have the setup (i.e. curl command or so) to then upload a demo via post at hand

[martig3]

No problem @markus-wa, thanks for the patch. I tested this with a few of my demo files and it appears to be working in my project branch here. When I have some more time I'll write some tests on my end but it appears to be working consistently enough for me at the moment.

[markus-wa]

awesome, thanks - I'll get a release out later this week

[markus-wa]

Just released v2.10.0 which should fix it.

I'm not 100% sure if this will cover all cases as it's a bit tricky to test - but if anyone is still experiencing issues please let me know and we can re-open this 🙂