[bug] panic when browsing to URL of a public reply

[LittleFox94]

Describe the bug with a clear and concise description of what the bug is.

Hi,

I told about this in chat before and was asked to raise a bug - with a comment of it might already have been fixed, it seems to ring a bell :)

We had a thread going on that started with public visibility and every reply to it was then unlisted visibility. The start of that thread and several posts in the reply-chain were from a user from another instance. At some point I posted a reply, specifying public visibility and hoping to have a shareable URL of some pictures - but browsing the post URL only gives a white page in chromium/a failed download attempt in firefox; GoToSocial ran into a panic - logs below.

The post in question is this: https://gotosocial-dev.svc.0x0a.network/@littlefox/statuses/01JJ454BRPWJA4M2ECQND40E4Q

timestamp="21/01/2025 15:50:10.138" func=server.init.func1.Logger.13.1 level=INFO latency="602.637µs" userAgent="Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36" method=GET statusCode=200 path=/@littlefox/statuses/01JJ454BRPWJA4M2ECQND40E4Q clientIP=202.61.208.66 errors="Error #01: recovered panic: runtime error: invalid memory address or nil pointer dereference\n" requestID=c970a76a4ec5b69139a246c0a84aba0a msg="OK: wrote 23B"
timestamp="21/01/2025 15:50:10.138" func=server.init.func1.Logger.13.1 level=ERROR stacktrace="()\n\t/usr/local/go/src/runtime/panic.go:261\nruntime.sigpanic()\n\t/usr/local/go/src/runtime/signal_unix.go:881\nweb.(*Module).threadGETHandler()\n\t/drone/src/internal/web/thread.go:111\n()\n\t/drone/src/vendor/github.com/gin-gonic/gin/context.go:185\ngzip.(*gzipHandler).Handle()\n\t/drone/src/vendor/github.com/gin-contrib/gzip/handler.go:60\ngin.(*Context).Next()\n\t/drone/src/vendor/github.com/gin-gonic/gin/context.go:185\nserver.init.func1.Logger.13()\n\t/drone/src/internal/middleware/logger.go:133\n()\n\t/drone/src/vendor/github.com/gin-gonic/gin/context.go:185\notelginmetrics.Middleware.func1()\n\t/drone/src/vendor/github.com/technologize/otel-go-contrib/otelginmetrics/middleware.go:68\n" requestID=c970a76a4ec5b69139a246c0a84aba0a msg="recovered panic: runtime error: invalid memory address or nil pointer dereference"

What's your GoToSocial Version?

0.17.2

GoToSocial Arch

amd64 docker-ish (Kubernetes, cri-o)

What happened?

Pointing a Browser at the URL of the post in question only gave an empty page, GoToSocial logged a panic.

What you expected to happen?

Seeing my post.

Since it was a reply to an unlisted post, I did not expect to see anything above it in the thread - basically just the post itself, just as if it wasn't a reply (or maybe a hint "Reply to a non-public post").

How to reproduce it?

• post something with public visibility -> post A
• reply to post A with unlisted visibility -> post B
• reply to post B with public visibility -> post C
• open browser to URL of post C

All those posts can be on the same instance, by the same user.

Anything else we need to know?

You are doing a great job and I can't wait for the next release 💙

[LittleFox94]

I took the stack trace apart for some better readability, but I'm afraid it's not looking too helpful:

()
	/usr/local/go/src/runtime/panic.go:261
runtime.sigpanic()
	/usr/local/go/src/runtime/signal_unix.go:881
web.(*Module).threadGETHandler()
	/drone/src/internal/web/thread.go:111
()
	/drone/src/vendor/github.com/gin-gonic/gin/context.go:185
gzip.(*gzipHandler).Handle()
	/drone/src/vendor/github.com/gin-contrib/gzip/handler.go:60
gin.(*Context).Next()
	/drone/src/vendor/github.com/gin-gonic/gin/context.go:185
server.init.func1.Logger.13()
	/drone/src/internal/middleware/logger.go:133
()
	/drone/src/vendor/github.com/gin-gonic/gin/context.go:185
otelginmetrics.Middleware.func1()
	/drone/src/vendor/github.com/technologize/otel-go-contrib/otelginmetrics/middleware.go:68

[LittleFox94]

Maybe-related issues are #3465 and #3341

#3465 defined "not serving public replies to non-public posts" as expected behavior, but that would make me sad - maybe reconsider together with what I wrote above in "What you expected to happen?"