x/tools/go/analysis/internal/checker: if offsetedit's start is 0, it can't be apply

[Abirdcfly]

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

$ go version
go version go1.19 darwin/amd64

Does this issue reproduce with the latest release?

Yes

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

go env Output

$ go env
GO111MODULE="auto"
GOARCH="amd64"
GOBIN="/usr/local/opt/go/libexec/bin"
GOCACHE="/Users/fupeng/Library/Caches/go-build"
GOENV="/Users/fupeng/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/fupeng/go/pkg/mod"
GONOPROXY="*tenxcloud.com"
GONOSUMDB="*tenxcloud.com"
GOOS="darwin"
GOPATH="/Users/fupeng/go"
GOPRIVATE="*tenxcloud.com"
GOPROXY="https://goproxy.cn"
GOROOT="/usr/local/opt/go/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/opt/go/libexec/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.19"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/fupeng/go/src/golang-tools/go.mod"
GOWORK=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/3v/mkwyck4x0f5bxv2gdv4_l8v00000gn/T/go-build515639227=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

I'm developing an linter to remove duplicate words from comments.(Yes, I know this scenario would be fine in many cases using the text tool, I just wanted to learn go ast by the way)

When my test file is as follows:

/*
package a
this comment include duplicated word and
and so the current line of `and` should 
be removed
*/
package a

After run dupword -fix ./... this file become :

package a

My analysis.Diagnostic.SuggestedFixes.TextEditsis

TextEdits: []analysis.TextEdit{{
						Pos:     c.Slash,
						End:     c.End(),
						NewText: []byte(update),
					}},

https://github.com/golang/tools/blob/248c34b88a4148128f89e41923498bd86f805b7d/go/analysis/internal/checker/checker.go#L377
change to offsetedit, the offsetedit.start is 0. And it is ignored in https://github.com/golang/tools/blob/master/go/analysis/internal/checker/checker.go#L408

What did you expect to see?

even if TextEdits.Pos is 0, it can be applied.

What did you see instead?

Just be deleted.

[gopherbot]

Change https://go.dev/cl/426654 mentions this issue: go/analysis/internal/checker: applyFixes condition changed to greater…

[heschi]

cc @matloob @timothy-king @zpavlinovic