fix forgotten TODO

2 files changed, 63 insertions, 8 deletions

diff --git a/all_test.go b/all_test.go
index 09e150d..2836dd9 100644
--- a/all_test.go
+++ b/all_test.go
@@ -21,6 +21,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -52,6 +53,23 @@ func dbg(s string, va ...interface{}) {
 	os.Stderr.Sync()
 }
 
+var traceLevel int32
+
+func trace() func() {
+	return func() {}
+	n := atomic.AddInt32(&traceLevel, 1)
+	pc, file, line, _ := runtime.Caller(1)
+	s := strings.Repeat("· ", int(n)-1)
+	fn := runtime.FuncForPC(pc)
+	fmt.Fprintf(os.Stderr, "%s# trace %s:%d:%s: in\n", s, path.Base(file), line, fn.Name())
+	os.Stderr.Sync()
+	return func() {
+		atomic.AddInt32(&traceLevel, -1)
+		fmt.Fprintf(os.Stderr, "%s# trace %s:%d:%s: out\n", s, path.Base(file), line, fn.Name())
+		os.Stderr.Sync()
+	}
+}
+
 func TODO(...interface{}) string { //TODOOK
 	_, fn, fl, _ := runtime.Caller(1)
 	return fmt.Sprintf("# TODO: %s:%d:\n", path.Base(fn), fl) //TODOOK
@@ -62,7 +80,7 @@ func stack() string { return string(debug.Stack()) }
 func use(...interface{}) {}
 
 func init() {
-	use(caller, dbg, TODO) //TODOOK
+	use(caller, dbg, TODO, trace) //TODOOK
 }
 
 // ============================================================================
@@ -377,6 +395,8 @@ func TestConcurrentGoroutines(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	defer db.Close()
+
 	tx, err := db.BeginTx(context.Background(), nil)
 	if err != nil {
 		t.Fatal(err)
@@ -681,6 +701,8 @@ func TestIssue20(t *testing.T) {
 		t.Fatalf("foo.db open fail: %v", err)
 	}
 
+	defer db.Close()
+
 	mustExec(t, db, "CREATE TABLE "+TablePrefix+"t (count INT)")
 	sel, err := db.PrepareContext(context.Background(), "SELECT count FROM "+TablePrefix+"t ORDER BY count DESC")
 	if err != nil {
@@ -723,3 +745,28 @@ func TestIssue20(t *testing.T) {
 		<-ch
 	}
 }
+
+func TestNoRows(t *testing.T) {
+	tempDir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer os.RemoveAll(tempDir)
+
+	db, err := sql.Open("sqlite", filepath.Join(tempDir, "foo.db"))
+	if err != nil {
+		t.Fatalf("foo.db open fail: %v", err)
+	}
+
+	defer db.Close()
+
+	stmt, err := db.Prepare("create table t(i);")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err := stmt.Query(); err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/sqlite.go b/sqlite.go
index 54549cf..73c3cd1 100644
--- a/sqlite.go
+++ b/sqlite.go
@@ -171,9 +171,10 @@ type rows struct {
 	pstmt   crt.Intptr
 
 	doStep bool
+	empty  bool
 }
 
-func newRows(c *conn, pstmt crt.Intptr, allocs []crt.Intptr) (r *rows, err error) {
+func newRows(c *conn, pstmt crt.Intptr, allocs []crt.Intptr, empty bool) (r *rows, err error) {
 	defer func() {
 		if err != nil {
 			c.finalize(pstmt)
@@ -218,6 +219,10 @@ func (r *rows) Columns() (c []string) {
 //
 // Next should return io.EOF when there are no more rows.
 func (r *rows) Next(dest []driver.Value) (err error) {
+	if r.empty {
+		return io.EOF
+	}
+
 	rc := bin.DSQLITE_ROW
 	if r.doStep {
 		if rc, err = r.c.step(r.pstmt); err != nil {
@@ -480,7 +485,7 @@ func (s *stmt) query(ctx context.Context, args []driver.NamedValue) (r driver.Ro
 
 			switch rc & 0xff {
 			case bin.DSQLITE_ROW:
-				if r, err = newRows(s.c, pstmt, allocs); err != nil {
+				if r, err = newRows(s.c, pstmt, allocs, false); err != nil {
 					return err
 				}
 
@@ -492,16 +497,19 @@ func (s *stmt) query(ctx context.Context, args []driver.NamedValue) (r driver.Ro
 				return s.c.errstr(int32(rc))
 			}
 
+			if *(*byte)(unsafe.Pointer(uintptr(psql))) == 0 {
+				if r, err = newRows(s.c, pstmt, allocs, true); err != nil {
+					return err
+				}
+
+				pstmt = 0
+			}
 			return nil
 		}(); err != nil {
 			return nil, err
 		}
 	}
-	if r != nil {
-		return r, nil
-	}
-
-	panic("TODO")
+	return r, err
 }
 
 type tx struct {