From b141129bda39ffa72610ea54cce60b589c217c44 Mon Sep 17 00:00:00 2001
From: pantor <lars.berscheid@online.de>
Date: Tue, 4 Aug 2020 23:19:55 +0200
Subject: [PATCH] fix segmentation fault

---
 include/inja/parser.hpp      | 6 +++---
 single_include/inja/inja.hpp | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/inja/parser.hpp b/include/inja/parser.hpp
index 23d869c..348f315 100644
--- a/include/inja/parser.hpp
+++ b/include/inja/parser.hpp
@@ -139,7 +139,7 @@ class Parser {
             add_json_literal(tmpl.content.c_str());
           }
 
-	// Operator
+	      // Operator
         } else if (tok.text == "and" || tok.text == "or" || tok.text == "in" || tok.text == "not") {
           goto parse_operator;
 
@@ -268,12 +268,12 @@ class Parser {
       } break;
       case Token::Kind::RightParen: {
         current_paren_level -= 1;
-        while (operator_stack.top()->operation != FunctionStorage::Operation::ParenLeft) {
+        while (!operator_stack.empty() && operator_stack.top()->operation != FunctionStorage::Operation::ParenLeft) {
           current_expression_list->rpn_output.emplace_back(operator_stack.top());
           operator_stack.pop();
         }
 
-        if (operator_stack.top()->operation == FunctionStorage::Operation::ParenLeft) {
+        if (!operator_stack.empty() && operator_stack.top()->operation == FunctionStorage::Operation::ParenLeft) {
           operator_stack.pop();
         }
 
diff --git a/single_include/inja/inja.hpp b/single_include/inja/inja.hpp
index 6a59abd..ec9937d 100644
--- a/single_include/inja/inja.hpp
+++ b/single_include/inja/inja.hpp
@@ -2851,7 +2851,7 @@ class Parser {
             add_json_literal(tmpl.content.c_str());
           }
 
-	// Operator
+	      // Operator
         } else if (tok.text == "and" || tok.text == "or" || tok.text == "in" || tok.text == "not") {
           goto parse_operator;
 
@@ -2980,12 +2980,12 @@ class Parser {
       } break;
       case Token::Kind::RightParen: {
         current_paren_level -= 1;
-        while (operator_stack.top()->operation != FunctionStorage::Operation::ParenLeft) {
+        while (!operator_stack.empty() && operator_stack.top()->operation != FunctionStorage::Operation::ParenLeft) {
           current_expression_list->rpn_output.emplace_back(operator_stack.top());
           operator_stack.pop();
         }
 
-        if (operator_stack.top()->operation == FunctionStorage::Operation::ParenLeft) {
+        if (!operator_stack.empty() && operator_stack.top()->operation == FunctionStorage::Operation::ParenLeft) {
           operator_stack.pop();
         }