net/mail: fails to escape address

[dvyukov]

The following program fails with the panic:

package main

import (
    "fmt"
    "net/mail"
)

func main() {
    data := "=??Q? ?=<0@0>"
    addr, err := mail.ParseAddress(data)
    if err != nil {
        return
    }
    _, err = mail.ParseAddress(addr.String())
    if err != nil {
        fmt.Printf("failed to parse addr: %q -> %q\n", data, addr)
        panic(err)
    }
}

failed to parse addr: "=??Q? ?=<0@0>" -> "\"=??Q? ?=\" <0@0>"
panic: mail: missing word in phrase: charset not supported: ""

That name should have been escaped.

go version devel +514014c Thu Jun 18 15:54:35 2015 +0200 linux/amd64

[rsc]

Dup of #11292.

[alexcesaro]

@rsc This issue is not a duplicate of #11292 and this code still panics on tip.

I will have a look during Go 1.7 dev cycle.

[bradfitz]

@alexcesaro, any chance you have time to look at this for 1.6 still? It would be nice to not have panics in code parsing random inputs.

[alexcesaro]

It is Dmitry's snippet above that panics not the net/mail code.

Also it is not a regression, that bug was discovered before Go 1.5 and is probably there since the beginning.

[bradfitz]

It is Dmitry's snippet above that panics not the net/mail code.

Sorry, I'm always confused by the reports saying "this code panics" when the code is just doing if err { panic }

[alexcesaro]

Yes sorry I wasn't clear :)

[rsc]

The fix for #11292 should have fixed this. If not we need to add a character or two to the base64 trigger the CL added. Russ

[alexcesaro]

I am on my phone but I don't think it is the same bug.

#11292 was an encoding issue. Here it is a parsing issue: the code thinks there is an encoded-word but it is not.

[rsc]

The first parse succeeds. Maybe that's a mistake, yes. But either way the resulting Addr - which could be created by direct field initialization instead - should survive the round trip `mail.ParseAddress(addr.String())`.

[gopherbot]

CL https://golang.org/cl/17381 mentions this issue.