internal/lsp: check InRange before calling token.Offset

This shows up every now and then--maybe we need a wrapper function around token.Offset to check the range. Updates golang/go#48249 Change-Id: I9c60bc7cc61fcfb2f4e8c6963586d8b8fbb21835 Reviewed-on: https://go-review.googlesource.com/c/tools/+/348429 Trust: Rebecca Stambler <[email protected]> Run-TryBot: Rebecca Stambler <[email protected]> Reviewed-by: Robert Findley <[email protected]> gopls-CI: kokoro <[email protected]> TryBot-Result: Go Bot <[email protected]>
golang · Sep 8, 2021 · 0a6f080 · 0a6f080
1 parent e5f719f
commit 0a6f080
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/internal/lsp/source/hover.go b/internal/lsp/source/hover.go
@@ -341,7 +341,9 @@ func HoverInfo(ctx context.Context, s Snapshot, pkg Package, obj types.Object, p
 			tok2 := s.FileSet().File(node.Pos())
 			var spec ast.Spec
 			for _, s := range node.Specs {
-				if tok2.Offset(s.Pos()) <= offset && offset <= tok2.Offset(s.End()) {
+				// Avoid panics by guarding the calls to token.Offset (golang/go#48249).
+				// TODO(rstambler): Investigate this further and adjust if needed.
+				if InRange(tok2, s.Pos()) && InRange(tok2, s.End()) && tok2.Offset(s.Pos()) <= offset && offset <= tok2.Offset(s.End()) {
 					spec = s
 					break
 				}