x/tools/gopls: crash in filepath.Walk during go.work completion

[muse-jimmy]

gopls version: v0.14.2 (go1.18rc1)
gopls flags:
update flags: proxy
extension version: 0.40.0
go version: 1.18rc1
environment: Visual Studio Code darwin
initialization error: undefined
issue timestamp: Fri, 17 Nov 2023 04:51:16 GMT
restart history:
Fri, 17 Nov 2023 03:37:10 GMT: activation (enabled: true)

ATTENTION: PLEASE PROVIDE THE DETAILS REQUESTED BELOW.

Describe what you observed.

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x18 pc=0x10125b7cc]

goroutine 12 [running]:
golang.org/x/tools/gopls/internal/lsp/work.Completion.func1({0x14000786740, 0x39}, {0x0%3F, 0x0%3F}, {0x1400033f368%3F, 0x1400073ad60%3F})
	  completion.go:88  0x10c
path/filepath.walk({0x1400073ad60, 0xf}, {0x1016dcda8, 0x140003a4f70}, 0x140003b3368)
	  path.go:438  0x180
path/filepath.walk({0x1400090edc0, 0x8}, {0x1016dcda8, 0x140001e1ee0}, 0x140003b3368)
	  path.go:442  0x1fc
path/filepath.walk({0x101b9af38, 0x1}, {0x1016dcda8, 0x1400018a0d0}, 0x140003b3368)
	  path.go:442  0x1fc
path/filepath.Walk({0x101b9af38, 0x1}, 0x1400036d368)
	  path.go:505  0x70
golang.org/x/tools/gopls/internal/lsp/work.Completion({0x1016da058%3F, 0x140003624e0%3F}, {0x1016df9c8, 0x14000254140}, {0x1016dae58, 0x140006f0720}, {0xa4091900%3F, 0xc14dda2c%3F})
	  completion.go:76  0x40c
golang.org/x/tools/gopls/internal/lsp.(*Server).completion(0x140002a0640%3F, {0x1016da058, 0x140003624e0}, 0x140002a0640)
	  completion.go:44  0x2d0
golang.org/x/tools/gopls/internal/lsp.(*Server).Completion(0x140001c2240%3F, {0x1016d9fb0%3F, 0x1400040e300%3F}, 0x10156d080%3F)
	  server_gen.go:28  0x28
golang.org/x/tools/gopls/internal/lsp/protocol.serverDispatch({0x1016d9fb0, 0x1400040e300}, {0x1016e28a0, 0x1400011a2d0}, 0x14000362180, {0x1016da2c0, 0x1400040e200})
	  tsserver.go:269  0x187c
golang.org/x/tools/gopls/internal/lsp/protocol.ServerHandler.func1({0x1016d9fb0, 0x1400040e300}, 0x14000362180, {0x1016da2c0, 0x1400040e200})
	  protocol.go:157  0x70
golang.org/x/tools/gopls/internal/lsp/lsprpc.handshaker.func1({0x1016d9fb0, 0x1400040e300}, 0x14000362180, {0x1016da2c0%3F, 0x1400040e200%3F})
	  lsprpc.go:521  0x788
golang.org/x/tools/internal/jsonrpc2.MustReplyHandler.func1({0x1016d9fb0, 0x1400040e300}, 0x140002850e0, {0x1016da2c0%3F, 0x1400040e200%3F})
	  handler.go:35  0xf4
golang.org/x/tools/internal/jsonrpc2.AsyncHandler.func1.2()
	  handler.go:103  0x90
created by golang.org/x/tools/internal/jsonrpc2.AsyncHandler.func1
	  handler.go:100  0x1dc
[Error - 1:50:58 PM] 

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[findleyr]

Thanks for the report!

Looks like the WalkFunc at that location needs to check for non-nil err and/or nil FileInfo.
We should reproduce first (chmod a file in a regtest?), and then fix.

This seems like a relatively rare occurrence, so I think this is fine to just fix in the next release.

Since this is a gopls issue, transferring to the Go issue tracker.

[gopherbot]

Change https://go.dev/cl/550376 mentions this issue: gopls/internal/work: fix crash during go.work completion