http: panic serving 172.16.0.3:55686: runtime error: invalid memory address or nil pointer dereference

[tomwilkie]

I'm seeing this quite often in my logs:

2015/09/14 03:56:21 http: panic serving 172.16.0.3:55686: runtime error: invalid memory address or nil pointer dereference
goroutine 194 [running]:
net/http.func·011()
    /usr/local/go/src/net/http/server.go:1130 +0xbb
compress/gzip.(*Reader).Close(0x0, 0x0, 0x0)
    /usr/local/go/src/compress/gzip/gunzip.go:287 +0x6c
main.func·008()
    /home/vagrant/src/github.com/weaveworks/scope/app/router.go:85 +0x39
main.func·009(0x7fd3033c3f10, 0xc2081434a0, 0xc2082fe340)
    /home/vagrant/src/github.com/weaveworks/scope/app/router.go:93 +0x230
net/http.HandlerFunc.ServeHTTP(0xc208130990, 0x7fd3033c3f10, 0xc2081434a0, 0xc2082fe340)
    /usr/local/go/src/net/http/server.go:1265 +0x41
github.com/gorilla/mux.(*Router).ServeHTTP(0xc20800ce60, 0x7fd3033c3f10, 0xc2081434a0, 0xc2082fe340)
    /home/vagrant/src/github.com/gorilla/mux/mux.go:98 +0x297
net/http.(*ServeMux).ServeHTTP(0xc20803a870, 0x7fd3033c3f10, 0xc2081434a0, 0xc2082fe340)
    /usr/local/go/src/net/http/server.go:1541 +0x17d
net/http.serverHandler.ServeHTTP(0xc2080625a0, 0x7fd3033c3f10, 0xc2081434a0, 0xc2082fe340)
    /usr/local/go/src/net/http/server.go:1703 +0x19a
net/http.(*conn).serve(0xc208143040)
    /usr/local/go/src/net/http/server.go:1204 +0xb57
created by net/http.(*Server).Serve
    /usr/local/go/src/net/http/server.go:1751 +0x35e

[tomwilkie]

According to the docs (http://golang.org/pkg/net/http/#Request):

// The Server will close the request body. The ServeHTTP
// Handler does not need to.

Seems to be coming from us closing the body on the server when the gzip decoding fails. Don't know why its failing, but we don't need to close the body.