database/sql: fix case where Stmt.Close discards error

Fixes a case where the Stmt.Close() function in database/sql discards any error generated by the Close() function of the contained driverStmt.

Fixes #12798

Change-Id: I40384d6165856665b062d15a643e4ecc09d63fda
Reviewed-on: https://go-review.googlesource.com/15178
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/database/sql/sql.go b/src/database/sql/sql.go
index 8a2d781330bead1379eff6926bfbe92fa479e486..fbb0e594a5a6b63abba8e72bc3c1ca1d2e15dc5f 100644 (file)
--- a/src/database/sql/sql.go
+++ b/src/database/sql/sql.go
@@ -1576,9 +1576,9 @@ func (s *Stmt) Close() error {
        s.closed = true
 
        if s.tx != nil {
-               s.txsi.Close()
+               err := s.txsi.Close()
                s.mu.Unlock()
-               return nil
+               return err
        }
        s.mu.Unlock()
 

diff --git a/src/database/sql/sql_test.go b/src/database/sql/sql_test.go
index b4135a3078210ac1670f1352a4dbe35d71c27f78..e1063bbc6b4509ae9c4ecfc15bbb5ceaf093631f 100644 (file)
--- a/src/database/sql/sql_test.go
+++ b/src/database/sql/sql_test.go
@@ -356,6 +356,44 @@ func TestStatementQueryRow(t *testing.T) {
        }
 }
 
+type stubDriverStmt struct {
+       err error
+}
+
+func (s stubDriverStmt) Close() error {
+       return s.err
+}
+
+func (s stubDriverStmt) NumInput() int {
+       return -1
+}
+
+func (s stubDriverStmt) Exec(args []driver.Value) (driver.Result, error) {
+       return nil, nil
+}
+
+func (s stubDriverStmt) Query(args []driver.Value) (driver.Rows, error) {
+       return nil, nil
+}
+
+// golang.org/issue/12798
+func TestStatementClose(t *testing.T) {
+       want := errors.New("STMT ERROR")
+
+       tests := []struct {
+               stmt *Stmt
+               msg  string
+       }{
+               {&Stmt{stickyErr: want}, "stickyErr not propagated"},
+               {&Stmt{tx: &Tx{}, txsi: &driverStmt{&sync.Mutex{}, stubDriverStmt{want}}}, "driverStmt.Close() error not propagated"},
+       }
+       for _, test := range tests {
+               if err := test.stmt.Close(); err != want {
+                       t.Errorf("%s. Got stmt.Close() = %v, want = %v", test.msg, err, want)
+               }
+       }
+}
+
 // golang.org/issue/3734
 func TestStatementQueryRowConcurrent(t *testing.T) {
        db := newTestDB(t, "people")