Repository: traefik/traefik (language: go)

Issue:
v2.8.2 go panic
### Welcome!

- [X] Yes, I've searched similar issues on [GitHub](https://github.com/traefik/traefik/issues) and didn't find any.
- [X] Yes, I've searched similar issues on the [Traefik community forum](https://community.traefik.io) and didn't find any.

### What did you do?

Watchtower upgraded to 2.8.2, I'm sourcing `latest`. Upgrade should have gone smoothly as usual.

### What did you see instead?

Go panic, can post full stack trace if necessary, its very large and hard to bound.

### What version of Traefik are you using?

```
Version:      2.8.2
Codename:     vacherin
Go version:   go1.19
Built:        2022-08-11T14:55:50Z
OS/Arch:      linux/amd64
```

### What is your environment & configuration?

Docker provider, cannot provide config (company/org). 2.8.1 works as expected.

### If applicable, please paste the log output in DEBUG level

```
 time="2022-08-11T17:16:16-03:00" level=error msg="Error in Go routine: runtime error: slice bounds out of range [2:1]"
traefik-traefik-1  | time="2022-08-11T17:16:16-03:00" level=error msg="Stack: goroutine 29 [running]:\nruntime/debug.Stack()\n\truntime/debug/stack.go:24 +0x65\ngithub.com/traefik/traefik/v2/pkg/safe.defaultRecoverGoroutine({0x36a75c0?, 0xc0007e40c0})\n\tgithub.com/traefik/traefik/v2/pkg/safe/routine.go:66 +0xa5\ngithub.com/traefik/traefik/v2/pkg/safe.GoWithRecover.func1.1()\n\tgithub.com/traefik/traefik/v2/pkg/safe/routine.go:56 +0x36\npanic({0x36a75c0, 0xc0007e40c0})\n\truntime/panic.go:884 +0x212\ngithub.com/traefik/paerser/parser.filler.setSlice({{0x19?, {0x3989c0e?, 0x0?}}}, {0x2ff49c0?, 0xc0004c91f8?, 0x355146f?}, 0xc0004d86c0)\n\tgithub.com/traefik/paerser@v0.1.6/parser/element_fill.go:157 +0xaa5\ngithub.com/traefik/paerser/pa
```

lots more, typical go stack trace. I can't reproduce this frequently, I need to get this server back to production.


Discussion / hints:

Fix patch:
diff --git a/go.mod b/go.mod
index 0e7ce8eed6..1e4a121c04 100644
--- a/go.mod
+++ b/go.mod
@@ -55,7 +55,7 @@ require (
 	github.com/sirupsen/logrus v1.8.1
 	github.com/stretchr/testify v1.8.0
 	github.com/stvp/go-udp-testing v0.0.0-20191102171040-06b61409b154
-	github.com/traefik/paerser v0.1.6
+	github.com/traefik/paerser v0.1.7
 	github.com/traefik/yaegi v0.14.1
 	github.com/uber/jaeger-client-go v2.30.0+incompatible
 	github.com/uber/jaeger-lib v2.2.0+incompatible
diff --git a/go.sum b/go.sum
index 4187850350..94e8b2c1e2 100644
--- a/go.sum
+++ b/go.sum
@@ -1903,8 +1903,8 @@ github.com/tonistiigi/units v0.0.0-20180711220420-6950e57a87ea h1:SXhTLE6pb6eld/
 github.com/tonistiigi/units v0.0.0-20180711220420-6950e57a87ea/go.mod h1:WPnis/6cRcDZSUvVmezrxJPkiO87ThFYsoUiMwWNDJk=
 github.com/tonistiigi/vt100 v0.0.0-20190402012908-ad4c4a574305 h1:y/1cL5AL2oRcfzz8CAHHhR6kDDfIOT0WEyH5k40sccM=
 github.com/tonistiigi/vt100 v0.0.0-20190402012908-ad4c4a574305/go.mod h1:gXOLibKqQTRAVuVZ9gX7G9Ykky8ll8yb4slxsEMoY0c=
-github.com/traefik/paerser v0.1.6 h1:UqqAW0M3r+aF7DibUVwO1PiZ8cXLsUkpFv5hhxPCscA=
-github.com/traefik/paerser v0.1.6/go.mod h1:Dk3Bfz6Zyj13/S8pJyRdx/FNvXlsVRVbtp0UK4ZSiA0=
+github.com/traefik/paerser v0.1.7 h1:xy84brL05/DMoff+KhY2ucq9+D3rnN9MH+3WtlmvvKU=
+github.com/traefik/paerser v0.1.7/go.mod h1:Dk3Bfz6Zyj13/S8pJyRdx/FNvXlsVRVbtp0UK4ZSiA0=
 github.com/traefik/yaegi v0.14.1 h1:t0ssyzeZCWTFGd/JnVuDxH/slMQfYg+2CDD4dLW/rU0=
 github.com/traefik/yaegi v0.14.1/go.mod h1:AVRxhaI2G+nUsaM1zyktzwXn69G3t/AuTDrCiTds9p0=
 github.com/transip/gotransip/v6 v6.6.1 h1:nsCU1ErZS5G0FeOpgGXc4FsWvBff9GPswSMggsC4564=


Test patch: