x/tools/gopls: rename panics if a test file exists

[fhs]

What version of Go are you using (go version)?

$ go version
go version devel +61bb56ad63 Mon Aug 12 23:12:29 2019 +0000 linux/amd64
$ gopls version
golang.org/x/tools/cmd/gopls v0.1.3-cmd.gopls
    golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3 h1:MVK2S/Gc+FEEuMU3i5K19MikzZsXixt3eMCaX2mCOfY=

What operating system and processor architecture are you using (go env)?

go env Output

$ go env | grep -v [private]
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/fhs/.cache/go-build"
GOENV="/home/fhs/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/fhs/go"
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/big/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/big/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/tmp/foo/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build173386163=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Create an example module:

$ mkdir /tmp/foo
$ cd /tmp/foo
$ cat > main.go
package main

import "fmt"

func main() {
	foo := 42
	fmt.Println(foo)
}
$ echo 'package main' > main_test.go
$ go mod init example.com/foo

Add /tmp/foo to VSCode workspace and then try to rename variable foo to bar.

What did you expect to see?

Successful rename.

What did you see instead?

gopls crashes:

[Trace - 5:15:21 AM] Sending notification 'textDocument/rename' in 1ms.
Params: {"textDocument":{"uri":"file:///tmp/foo/main.go"},"position":{"line":5,"character":2},"newName":"bar"}


[Error - 5:15:21 AM] Request textDocument/rename failed.
  Message: method "textDocument/rename" did not reply
  Code: -32603 
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x40 pc=0x797a72]

goroutine 1402 [running]:
golang.org/x/tools/internal/lsp/source.forEachLexicalRef(0xbf6040, 0xc002506a80, 0x0, 0x0, 0xc015a0, 0xc001d52cd0, 0xc0024d7000, 0xc0002e8700)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/lsp/source/rename_check.go:334 +0x112
golang.org/x/tools/internal/lsp/source.(*renamer).checkInLexicalScope(0xc001a464d0, 0xc015a0, 0xc001d52cd0, 0x0, 0x0)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/lsp/source/rename_check.go:214 +0xe8
golang.org/x/tools/internal/lsp/source.(*renamer).checkInLocalScope(0xc001a464d0, 0xc015a0, 0xc001d52cd0)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/lsp/source/rename_check.go:144 +0x98
golang.org/x/tools/internal/lsp/source.(*renamer).check(0xc001a464d0, 0xc015a0, 0xc001d52cd0)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/lsp/source/rename_check.go:49 +0x1e7
golang.org/x/tools/internal/lsp/source.(*IdentifierInfo).Rename(0xc0024fe5b0, 0xbf6040, 0xc002506a80, 0xc00230cd10, 0x3, 0x0, 0x0, 0x0)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/lsp/source/rename.go:82 +0x4af
golang.org/x/tools/internal/lsp.(*Server).rename(0xc00017b9a0, 0xbf6040, 0xc00251fa10, 0xc0025068a0, 0x0, 0x0, 0xc001a46370)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/lsp/rename.go:34 +0x281
golang.org/x/tools/internal/lsp.(*Server).Rename(0xc00017b9a0, 0xbf6040, 0xc00251fa10, 0xc0025068a0, 0xc0025068a0, 0x0, 0x0)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/lsp/server.go:253 +0x49
golang.org/x/tools/internal/lsp/protocol.serverHandler.Deliver(0xc07280, 0xc00017b9a0, 0xbf6040, 0xc00251fa10, 0xc0024d2bc0, 0xc00251fa00, 0xc0024a8b90)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/lsp/protocol/tsserver.go:466 +0xf47
golang.org/x/tools/internal/jsonrpc2.(*Conn).Run.func1(0xc001ec43c0, 0xc0024d2bc0, 0xc0000b7c80, 0xbf6040, 0xc00251fa10, 0x0, 0x0, 0xc0024f44b0)
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/jsonrpc2/jsonrpc2.go:370 +0x170
created by golang.org/x/tools/internal/jsonrpc2.(*Conn).Run
	/home/fhs/go/pkg/mod/golang.org/x/tools@v0.0.0-20190814235402-ea4142463bf3/internal/jsonrpc2/jsonrpc2.go:354 +0x86a
[Info  - 5:15:21 AM] Connection to server got closed. Server will restart.

Note: rename is successful if you remove main_test.go.

[suzmue]

Thanks for the repro! Found the bug and am sending a fix.

[gopherbot]

Change https://golang.org/cl/190399 mentions this issue: internal/lsp: fix bug to add all packages to map for checking