internal/span: catch potential panics in go/token
Updates golang/go#32639
Change-Id: Ib413fc316af4308d8928647ff36a437d243a9c11
Reviewed-on: https://go-review.googlesource.com/c/tools/+/184038
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
diff --git a/internal/span/token.go b/internal/span/token.go
index 406da4a..4efd0c8 100644
--- a/internal/span/token.go
+++ b/internal/span/token.go
@@ -99,6 +99,14 @@
if err != nil {
return Range{}, err
}
+ // go/token will panic if the offset is larger than the file's size,
+ // so check here to avoid panicking.
+ if s.Start().Offset() > converter.file.Size() {
+ return Range{}, fmt.Errorf("start offset %v is past the end of the file", s.Start())
+ }
+ if s.End().Offset() > converter.file.Size() {
+ return Range{}, fmt.Errorf("end offset %v is past the end of the file", s.End())
+ }
return Range{
FileSet: converter.fset,
Start: converter.file.Pos(s.Start().Offset()),
@@ -107,7 +115,9 @@
}
func (l *TokenConverter) ToPosition(offset int) (int, int, error) {
- //TODO: check offset fits in file
+ if offset > l.file.Size() {
+ return 0, 0, fmt.Errorf("offset %v is past the end of the file", offset)
+ }
pos := l.file.Pos(offset)
p := l.fset.Position(pos)
return p.Line, p.Column, nil
