internal/lsp: add additional check for analysis value

Updates golang/go#35339 Change-Id: Ie990672b619d1844f66abf62010fe9a69daf00d9 Reviewed-on: https://go-review.googlesource.com/c/tools/+/205161 Run-TryBot: Rebecca Stambler <rstambler@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Cottrell <iancottrell@google.com>

Author: stamblerre

internal/lsp/cache/analysis.go

@@ -131,8 +131,7 @@ func (s *snapshot) actionHandle(ctx context.Context, id packageID, mode source.P
 err: err,
 }
 }
-data := runAnalysis(ctx, fset, a, pkg, results)
-return data
+return runAnalysis(ctx, fset, a, pkg, results)
 })
 ah.handle = h
 
@@ -145,7 +144,10 @@ func (act *actionHandle) analyze(ctx context.Context) ([]*source.Error, interfac
 if v == nil {
 return nil, nil, errors.Errorf("no analyses for %s", act.pkg.ID())
 }
-data := v.(*actionData)
+data, ok := v.(*actionData)
+if !ok {
+return nil, nil, errors.Errorf("unexpected type for %s:%s", act.pkg.ID(), act.analyzer.Name)
+}
 return data.diagnostics, data.result, data.err
 }
 
@@ -154,7 +156,10 @@ func (act *actionHandle) cached() ([]*source.Error, interface{}, error) {
 if v == nil {
 return nil, nil, errors.Errorf("no analyses for %s", act.pkg.ID())
 }
-data := v.(*actionData)
+data, ok := v.(*actionData)
+if !ok {
+return nil, nil, errors.Errorf("unexpected type for %s:%s", act.pkg.ID(), act.analyzer.Name)
+}
 return data.diagnostics, data.result, data.err
 }