Logger panics after SetHeader with empty string

[glumpo]

Issue Description

Checklist

• Dependencies installed
• No typos
• Searched existing issues and docs

Expected behaviour

package main

import (
	"github.com/labstack/echo/v4"
)

func main() {
	e := echo.New()
	e.Logger.SetHeader("")
	e.Logger.Error("Hellow")
}

I expect code above to print just a message "Hellow"

Actual behaviour

Code panics.

Steps to reproduce

go run ./main.go with code above.

Version/commit

v4.9.0
Also checked on latest commit 666938e

[glumpo]

Issue is already fixed in logger
https://github.com/labstack/gommon/blob/6267eb7480ded0b4c030ca5e7320417281bb4cd6/log/log.go#L394

Will you update dependency, or we are waiting for release or something?

[aldas]

I'll bump version soon.

Are you trying to disable logger or why are you setting header to empty string?

[glumpo]

Hi, thanks for reply.
I want to provide server with my logger, but not satisfying echo.Logger interface for some reasons (mainly it looks too detailed). So I tried to set empty header and provide io.Writer (throw SetOutput), which will merge echo`s logs to my main logger.

[aldas]

@glumpo what are you logging? If its requests then I strongly suggest you to use newer logger middleware https://github.com/labstack/echo/blob/master/middleware/request_logger.go See examples there at the beginning. RequestLogger middleware is built to be used with 3rd party logger libraries (like Zap, Zerolog etc).

[glumpo]

@aldas Thanks for suggestion I already use RequestLogger for requests. But as I can see Logger is used for some internal purposes in Response.WriteHeader and in Router.Add. I guess I probably will never need to see logs from Router.Add but I am not sure about WriteHeader and possible future changes, which may add more internal logging.

[aldas]

This is fixed in v4.9.1. I bumped gommon version.