go/internal/gcimporter: return (possibly incomplete) package in case of error

For #16088.

Change-Id: Ib38bda06a5c5d110ca86510043775c5cf229e6a8
Reviewed-on: https://go-review.googlesource.com/37756
Reviewed-by: Alan Donovan <adonovan@google.com>

diff --git a/src/go/internal/gcimporter/bimport.go b/src/go/internal/gcimporter/bimport.go
index 5badd337d9fc5874ed8b15aca15d381aaaf2a4c0..e38570d97bbf1aa20849ec80909cd9f197288ac3 100644 (file)
--- a/src/go/internal/gcimporter/bimport.go
+++ b/src/go/internal/gcimporter/bimport.go
@@ -47,12 +47,13 @@ type importer struct {
 // and returns the number of bytes consumed and a reference to the package.
 // If the export data version is not recognized or the format is otherwise
 // compromised, an error is returned.
-func BImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, _ *types.Package, err error) {
+func BImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, pkg *types.Package, err error) {
        // catch panics and return them as errors
        defer func() {
                if e := recover(); e != nil {
                        // The package (filename) causing the problem is added to this
                        // error by a wrapper in the caller (Import in gcimporter.go).
+                       // Return a (possibly nil or incomplete) package unchanged (see #16088).
                        err = fmt.Errorf("cannot import, possibly version skew (%v) - reinstall package", e)
                }
        }()
@@ -117,7 +118,7 @@ func BImportData(fset *token.FileSet, imports map[string]*types.Package, data []
        p.typList = append(p.typList, predeclared...)
 
        // read package data
-       pkg := p.pkg()
+       pkg = p.pkg()
 
        // read objects of phase 1 only (see cmd/compiler/internal/gc/bexport.go)
        objcount := 0