Panic in FilterIssues with a coment without a position

[fortytw2]

Not entirely sure what happened here, but the Github status check seems to be stuck in yellow

PR - https://github.com/fortytw2/hydrocarbon/pull/51 GopherCI - https://gci.gopherci.io/analysis/329

[bradleyfalzon]

Thanks @fortytw2, the issue is with a panic on line https://github.com/bradleyfalzon/gopherci/blob/bafe2bb3318e34e0b92d39514b219555b942bb4a/internal/github/installation.go#L124

May 02 06:42:06 www1 gopherci[10430]: panic: runtime error: invalid memory address or nil pointer dereference
May 02 06:42:06 www1 gopherci[10430]: [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x80f4f2]
May 02 06:42:06 www1 gopherci[10430]: goroutine 23306 [running]:
May 02 06:42:06 www1 gopherci[10430]: github.com/bradleyfalzon/gopherci/internal/github.(*Installation).FilterIssues(0xc420362850, 0x11326a0, 0xc4202eba40, 0xc420341000, 0x8, 0xc420341044, 0xb, 0x33, 0xc4205d5140, 0x1, ...)
May 02 06:42:06 www1 gopherci[10430]: /data/gopherci-2017-04-27-141809/src/github.com/bradleyfalzon/gopherci/internal/github/installation.go:124 +0x232
May 02 06:42:06 www1 gopherci[10430]: github.com/bradleyfalzon/gopherci/internal/github.(*GitHub).Analyse(0xc4201b8480, 0x1, 0x18e2, 0x37b35a9, 0xbc61d1, 0xe, 0xc42075d7a0, 0x63, 0x0, 0x0, ...)
May 02 06:42:06 www1 gopherci[10430]: /data/gopherci-2017-04-27-141809/src/github.com/bradleyfalzon/gopherci/internal/github/handlers.go:382 +0xb23
May 02 06:42:06 www1 gopherci[10430]: main.(*queueProcessor).Process(0xc42018c108, 0xace060, 0xc420619380)
May 02 06:42:06 www1 gopherci[10430]: /data/gopherci-2017-04-27-141809/src/github.com/bradleyfalzon/gopherci/main.go:212 +0x585
May 02 06:42:06 www1 gopherci[10430]: main.(*queueProcessor).Process-fm(0xace060, 0xc420619380)
May 02 06:42:06 www1 gopherci[10430]: /data/gopherci-2017-04-27-141809/src/github.com/bradleyfalzon/gopherci/main.go:152 +0x3e
May 02 06:42:06 www1 gopherci[10430]: github.com/bradleyfalzon/gopherci/internal/queue.(*GCPPubSubQueue).receive.func1(0x7fe427eee2c8, 0xc42043c640, 0xc420409c00)
May 02 06:42:06 www1 gopherci[10430]: /data/gopherci-2017-04-27-141809/src/github.com/bradleyfalzon/gopherci/internal/queue/gcp-pubsub.go:174 +0x5b1
May 02 06:42:06 www1 gopherci[10430]: cloud.google.com/go/pubsub.(*Subscription).receive.func2(0xc4203a7770, 0xc420183c80, 0xc420409c00, 0xc4203bcc70, 0x7fe427eee2c8, 0xc42043c640)
May 02 06:42:06 www1 gopherci[10430]: /data/gopherci-2017-04-27-141809/src/cloud.google.com/go/pubsub/subscription.go:286 +0xa2
May 02 06:42:06 www1 gopherci[10430]: created by cloud.google.com/go/pubsub.(*Subscription).receive
May 02 06:42:06 www1 gopherci[10430]: /data/gopherci-2017-04-27-141809/src/cloud.google.com/go/pubsub/subscription.go:287 +0x26f

[bradleyfalzon]

OK, it appears a pull request comment can have a null position: https://api.github.com/repos/fortytw2/hydrocarbon/pulls/51/comments

[
  {
    "url": "https://api.github.com/repos/fortytw2/hydrocarbon/pulls/comments/114151771",
    "pull_request_review_id": 35595050,
    "id": 114151771,
    "diff_hunk": "@@ -14,10 +15,19 @@ type MockMailer struct {\n func (mm *MockMailer) Send(email string, body string) error {\n \treturn nil\n }\n+func (mm *MockMailer) RootDomain() string {",
    "path": "mailer.go",
    "position": null,
    "original_position": 12,

I'll fix this up, but this also highlights the fact I need better panic handling, which I'll have a closer look at where the best point is for this. As I'd like to mark the build as failed due to internal error, but perhaps continue the panic and let it restart itself back to a known good state.

[bradleyfalzon]

Fixed via 8dff2ea8318145488a3f26485d09f233d31eac43 and better handling of panics in general via 7318f06305f227b9c09ab87bb3523e77e534d8a7. Deploying now.

[bradleyfalzon]

Thanks @fortytw2 shouldn't happen again and we have better handling for these cases now.

[bradleyfalzon]

oh, and kicked off the job again so https://github.com/fortytw2/hydrocarbon/pull/51 is passing not stuck pending.