Merge pull request #204 from edznux-dd/nil-pointer-deref

[bugfix] Nil pointer deref

Author: huandu

select_test.go

@@ -417,3 +417,8 @@ func ExampleSelectBuilder_LateralAs() {
 	// Output:
 	// SELECT salesperson.name, max_sale.amount, max_sale.customer_name FROM salesperson, LATERAL (SELECT amount, customer_name FROM all_sales WHERE all_sales.salesperson_id = salesperson.id ORDER BY amount DESC LIMIT ?) AS max_sale
 }
+
+func TestNilPointerWhere(t *testing.T) {
+	NewSelectBuilder().SQL("$0").Build()
+	NewSelectBuilder().SQL("$0").BuildWithFlavor(DefaultFlavor)
+}

whereclause.go

@@ -60,7 +60,7 @@ var _ Builder = new(whereClauseProxy)
 
 // BuildWithFlavor builds a WHERE clause with the specified flavor and initial arguments.
 func (wc *WhereClause) BuildWithFlavor(flavor Flavor, initialArg ...interface{}) (sql string, args []interface{}) {
-	if len(wc.clauses) == 0 {
+	if wc == nil || len(wc.clauses) == 0 {
 		return "", nil
 	}
 
@@ -128,6 +128,9 @@ func (wc *WhereClause) AddWhereExpr(args *Args, andExpr ...string) *WhereClause
 
 // AddWhereClause adds all clauses in the whereClause to the wc.
 func (wc *WhereClause) AddWhereClause(whereClause *WhereClause) *WhereClause {
+	if wc == nil {
+		return nil
+	}
 	if whereClause == nil {
 		return wc
 	}