nil pointer dereference when running tailscale netcheck #5919
Description
What is the issue?
Running tailscale netcheck while connected to an exit node causes a nil pointer deref.
Client: Tailscale 1.32.0 on Windows 11 (22H2)
Exit Node: Tailscale 1.32.0 on Windows 10 (21H2)
Steps to reproduce
C:\Users\Nebula>tailscale netcheck
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x0 pc=0x1378238]
goroutine 175 [running]:
tailscale.com/derp/derphttp.(*Client).Close(0xc00069c2d0)
tailscale.com@v1.32.0/derp/derphttp/derphttp_client.go:988 +0x38
tailscale.com/net/netcheck.(*Client).measureHTTPSLatency(0xc000240000, {0x15f3668, 0xc0002802a0}, 0x0?)
tailscale.com@v1.32.0/net/netcheck/netcheck.go:1195 +0xa7c
tailscale.com/net/netcheck.(*Client).GetReport.func8(0xc0002b6640)
tailscale.com@v1.32.0/net/netcheck/netcheck.go:1033 +0x97
created by tailscale.com/net/netcheck.(*Client).GetReport
tailscale.com@v1.32.0/net/netcheck/netcheck.go:1031 +0x1c72
Are there any recent changes that introduced the issue?
No response
OS
Windows
OS version
22H2
Tailscale version
1.32.0
Bug report
BUG-a01c06d9d3e148a6c8c549f5ac2362b66b80190e0c272eed365057a70efa314f-20221013140405Z-6b8508d4502d0499