Context.Bind does not recover from panic

[Paulius-Maruska]

Description

Context.Bind does not always return the error, namely - if there is a panic call - Context.Bind will not recover from it.

Expected behaviour

Context.Bind return type is error - the expectation is that any and all errors that occur within will be returned.

Actual behaviour

Context.Bind does not recover from panic, so some errors are not returned - instead they crash the handler function.

Working code to debug

package main

import (
    "fmt"

    "github.com/labstack/echo"
    "github.com/labstack/echo/engine/standard"
)

func main() {
    app := echo.New()
    app.POST("/handler", func(c echo.Context) error {
        var obj = make([]struct{ Field string }, 0)
        if e := c.Bind(&obj); e != nil {
            return c.String(400, fmt.Sprintf("Error\n%v\n", e))
        }
        return c.String(200, fmt.Sprintf("Request data parsed succesfully\n"))
    })
    app.Run(standard.New(":8081"))
}

The way to make a panic condition (that I found) - you can send JSON content with wrong content-type header value, for example:

curl -X POST -H "Content-Type: application/x-www-form-urlencoded" -d '[{"Field": "foo"},{"Field": "foo"}]' http://localhost:8081/handler

This causes a panic within a standard library and it is not handled by Context.Bind. This means, that instead of returning error to the handler, so that the handler could return 400 status code - it simply crashes the entire handler coroutine.

Version/commit

I found and tested this on echo fbcdf70

[dotpot]

👍

[o1egl]

Fixed #579

[vishr]

@Paulius-Maruska Please verify.

[Paulius-Maruska]

Sorry for not responding sooner. Yes, that particular bug with wrong content-type no longer panics. Thank you.