Crash caught when formting markdown link

[Arkaeriit]

I tried to send [](https://xkcd.com/949/) and I got:

        [running]: runtime/debug.Stack()

        ┃ /snap/go/current/src/runtime/debug/stack.go:24 +0x65
        ┃ 

        main.protectFromPanic()

        ┃ /home/ubuntu/devzat/util.go:109 +0x5f
        ┃ 

        panic({0xe50200, 0x17a61a0})

        ┃ /snap/go/current/src/runtime/panic.go:884 +0x213
        ┃ 

        github.com/quackduck/go-term-markdown.(*renderer).RenderNode(0xc0000f0420, {0x1180fe0, 0xc000090000}, {0x118a660?, 0xc000538b60?}, 0x1)

        ┃ /home/ubuntu/go/pkg/mod/github.com/quackduck/go-term-markdown@v0.14.2/renderer.go:310 +0x1381
        ┃ 

        github.com/gomarkdown/markdown.Render.func1({0x118a660?, 0xc000538b60?}, 0x20?)

        ┃ /home/ubuntu/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230322041520-c84983bdbf2a/markdown.go:63 +0x47
        ┃ 

        github.com/gomarkdown/markdown/ast.NodeVisitorFunc.Visit(0x118a810?, {0x118a660?, 0xc000538b60?}, 0xe0?)

        ┃ /home/ubuntu/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230322041520-c84983bdbf2a/ast/node.go:574 +0x2e
        ┃ 

        github.com/gomarkdown/markdown/ast.Walk({0x118a660, 0xc000538b60}, {0x1183760, 0xc000078d60})

        ┃ /home/ubuntu/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230322041520-c84983bdbf2a/ast/node.go:546 +0x59
        ┃ 

        github.com/gomarkdown/markdown/ast.Walk({0x118a810, 0xc000131380}, {0x1183760, 0xc000078d60})

        ┃ /home/ubuntu/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230322041520-c84983bdbf2a/ast/node.go:557 +0x145
        ┃ 

        github.com/gomarkdown/markdown/ast.Walk({0x118a348, 0xc000131320}, {0x1183760, 0xc000078d60})

        ┃ /home/ubuntu/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230322041520-c84983bdbf2a/ast/node.go:557 +0x145
        ┃ 

        github.com/gomarkdown/markdown/ast.WalkFunc(...)

        ┃ /home/ubuntu/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230322041520-c84983bdbf2a/ast/node.go:580
        ┃ 

        github.com/gomarkdown/markdown.Render({0x118a348, 0xc000131320}, {0x1187d10, 0xc0000f0420})

        ┃ /home/ubuntu/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230322041520-c84983bdbf2a/markdown.go:62 +0xd7
        ┃ 

        github.com/quackduck/go-term-markdown.Render({0xc000820ac0, 0x1a}, 0xf4e1c3?, 0x2?, {0x0, 0x0, 0x0})

        ┃ /home/ubuntu/go/pkg/mod/github.com/quackduck/go-term-markdown@v0.14.2/markdown.go:32 +0xbe
        ┃ 

        main.mdRender({0xc000820aa0?, 0x4?}, 0x6, 0xbf)

        ┃ /home/ubuntu/devzat/util.go:134 +0x10f
        ┃

        main.(*User).writeln(0xc00057a900, {0xc00077ee28, 0x13}, {0xc000820aa0, 0x19})

        ┃ /home/ubuntu/devzat/main.go:583 +0x291
        ┃

        main.(*Room).broadcastNoBridges(0x17b05e0, {0xc00077ee28, 0x13}, {0xc000820aa0, 0x19})

        ┃ /home/ubuntu/devzat/main.go:266 +0x125
        ┃

        main.(*Room).broadcast(0x17b05e0?, {0xc00077ee28?, 0x13?}, {0xc000820aa0?, 0x19?})

        ┃ /home/ubuntu/devzat/main.go:217 +0x348
        ┃

        main.runCommands({0xc000820a00?, 0xc000346330?}, 0xc00020e400)

        ┃ /home/ubuntu/devzat/commands.go:121 +0x432
        ┃

        main.(*User).repl(0xc00020e400)

        ┃ /home/ubuntu/devzat/main.go:804 +0x445
        ┃

        main.main.func3({0x1190bd8?, 0xc00029a340})

        ┃ /home/ubuntu/devzat/main.go:152 +0xaf
        ┃

        github.com/gliderlabs/ssh.(*session).handleRequests.func1()

        ┃ /home/ubuntu/go/pkg/mod/github.com/gliderlabs/ssh@v0.3.5/session.go:261 +0x2d
        ┃

        created by github.com/gliderlabs/ssh.(*session).handleRequests

        ┃ /home/ubuntu/go/pkg/mod/github.com/gliderlabs/ssh@v0.3.5/session.go:260 +0x51c
        ┃

[quackduck]

Looks like the error happens on this line in the renderer:

https://github.com/quackduck/go-term-markdown/blob/v0.14.2/renderer.go#LL310C3-L310C3

Very strange

[quackduck]

Well actually it makes sense right? If you're trying to link something you need to give the link some display text, right?

Of course, a panic is the wrong way to respond to this, but also it doesn't crash the server lol. So we have two options, make the renderer return an error or just don't do anything.

[Arkaeriit]

Even with a text, the renderer does not changes the output much. I think the render should just display input text in this case.

[quackduck]

do you mean just the link text?

[Arkaeriit]

I mean if I type [](http://exmaple.com), the markdown renderer outputs [](http://exmaple.com).

[quackduck]

What should it output?