Fix _auth_* parameter check

Fixes: #724

sqlite3.go

@@ -1522,10 +1522,10 @@ func (d *SQLiteDriver) Open(dsn string) (driver.Conn, error) {
 		// Before going any further, we need to check that the user
 		// has provided an username and password within the DSN.
 		// We are not allowed to continue.
-		if len(authUser) < 0 {
+		if len(authUser) <= 0 {
 			return nil, fmt.Errorf("Missing '_auth_user' while user authentication was requested with '_auth'")
 		}
-		if len(authPass) < 0 {
+		if len(authPass) <= 0 {
 			return nil, fmt.Errorf("Missing '_auth_pass' while user authentication was requested with '_auth'")
 		}
 

sqlite3_opt_userauth_test.go

@@ -60,7 +60,14 @@ func init() {
 			file = TempFilename(t)
 		}
 
-		db, err = sql.Open("sqlite3_with_conn", "file:"+file+fmt.Sprintf("?_auth&_auth_user=%s&_auth_pass=%s", username, password))
+		params := "?_auth"
+		if len(username) > 0 {
+			params = fmt.Sprintf("%s&_auth_user=%s", params, username)
+		}
+		if len(password) > 0 {
+			params = fmt.Sprintf("%s&_auth_pass=%s", params, password)
+		}
+		db, err = sql.Open("sqlite3_with_conn", "file:"+file+params)
 		if err != nil {
 			defer os.Remove(file)
 			return file, nil, nil, err
@@ -164,6 +171,23 @@ func TestUserAuthCreateDatabase(t *testing.T) {
 	}
 }
 
+func TestUserAuthCreateDatabaseWithoutArgs(t *testing.T) {
+	_, db, c, err := connect(t, "", "", "")
+	if err == nil && c == nil && db == nil {
+		t.Fatal("Should have failed due to missing _auth_* parameters")
+	}
+
+	_, db, c, err = connect(t, "", "", "admin")
+	if err == nil && c == nil && db == nil {
+		t.Fatal("Should have failed due to missing _auth_user parameter")
+	}
+
+	_, db, c, err = connect(t, "", "admin", "")
+	if err == nil && c == nil && db == nil {
+		t.Fatal("Should have failed due to missing _auth_pass parameter")
+	}
+}
+
 func TestUserAuthLogin(t *testing.T) {
 	f1, err := create(t, "admin", "admin")
 	if err != nil {