Blob I/O: insufficient space errors for Write, raw connection callback

Author: joriszwart

blob_io.go

@@ -87,14 +87,18 @@ func (s *SQLiteBlob) Read(b []byte) (n int, err error) {
 // Write implements the io.Writer interface.
 func (s *SQLiteBlob) Write(b []byte) (n int, err error) {
 	if s.offset >= s.size {
-		return 0, io.EOF
+		return 0, fmt.Errorf("sqlite3.SQLiteBlob.Write: insufficient space in %d-byte blob", s.size)
 	}
 
 	n = s.size - s.offset
 	if len(b) < n {
 		n = len(b)
 	}
 
+	if n != len(b) {
+		return n, fmt.Errorf("sqlite3.SQLiteBlob.Write: insufficient space in %d-byte blob", s.size)
+	}
+
 	p := &b[0]
 	ret := C.sqlite3_blob_write(s.blob, unsafe.Pointer(p), C.int(n), C.int(s.offset))
 	if ret != C.SQLITE_OK {

blob_io_test.go

@@ -56,15 +56,14 @@ func blobTestData(t *testing.T, dbname string, rowid int64, blob []byte, c drive
 	var driverConn *SQLiteConn
 	err = conn.Raw(func(conn interface{}) error {
 		driverConn = conn.(*SQLiteConn)
+		c(t, driverConn)
 		return nil
 	})
 	if err != nil {
 		return err
 	}
 	defer driverConn.Close()
 
-	c(t, driverConn)
-
 	return nil
 }
 
@@ -162,12 +161,12 @@ func TestBlobWrite(t *testing.T) {
 			t.Errorf("Failed to write %d bytes", n2)
 		}
 
-		// EOF
+		// Insufficient space
 		b3 := make([]byte, 10)
 		n3, err := blob.Write(b3)
 
-		if err != io.EOF || n3 != 0 {
-			t.Error("Expected EOF", err)
+		if err.Error() != "sqlite3.SQLiteBlob.Write: insufficient space in 24-byte blob" || n3 != 0 {
+			t.Error("Expected insufficient space error", err, n3)
 		}
 
 		// Verify written data