From ad9e3e6bad7b0d918eb77784bfeb3465710e9a5c Mon Sep 17 00:00:00 2001
From: Valeriano Alfonso Rodriguez <valen.alfonso@gmail.com>
Date: Thu, 14 Oct 2021 20:07:36 +0200
Subject: [PATCH] Parser.ParseBooleanOp: Parse failure with multiple "And" "Or"
 chained

---
 VAR.ExpressionEvaluator.Tests/ParserTests.cs | 18 +++++++++++++++++-
 VAR.ExpressionEvaluator/Parser.cs            |  4 ++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/VAR.ExpressionEvaluator.Tests/ParserTests.cs b/VAR.ExpressionEvaluator.Tests/ParserTests.cs
index d8574b1..c142532 100644
--- a/VAR.ExpressionEvaluator.Tests/ParserTests.cs
+++ b/VAR.ExpressionEvaluator.Tests/ParserTests.cs
@@ -664,7 +664,7 @@ namespace VAR.ExpressionEvaluator.Tests
 
         #endregion String coercions
 
-        #region Excepctions
+        #region Exceptions
 
         [Fact]
         public void Exceptions__HelloAtEnd__UnexpectedCharactersAtEndException()
@@ -848,6 +848,22 @@ namespace VAR.ExpressionEvaluator.Tests
         }
 
 
+        #endregion Exceptions
+
+        #region Misc
+
+        [Fact()]
+        public void Misc__MixedExpression_EqualsFalse()
+        {
+            EvaluationContext evaluationContex = new EvaluationContext();
+            evaluationContex.SetVariable("QI_86", null);
+            evaluationContex.SetVariable("QI_87", null);
+            evaluationContex.SetVariable("QI_104", null);
+            string expression = "( QI_86 = 0 Or QI_86 = null ) And ( QI_87 = 0 Or QI_87 = null ) And QI_104 > 0";
+            object result = Parser.EvaluateString(expression, evaluationContex);
+            Assert.False((bool?)result);
+        }
+
         #endregion Misc
     }
 }
\ No newline at end of file
diff --git a/VAR.ExpressionEvaluator/Parser.cs b/VAR.ExpressionEvaluator/Parser.cs
index 81be887..055a089 100644
--- a/VAR.ExpressionEvaluator/Parser.cs
+++ b/VAR.ExpressionEvaluator/Parser.cs
@@ -60,7 +60,7 @@ namespace VAR.ExpressionEvaluator
                     IExpressionNode rightNode = ParseRelations();
                     leftNode = new ExpressionBooleanAndNode(leftNode, rightNode);
                 }
-                if (_tokenizer.Token == Token.Or)
+                else if (_tokenizer.Token == Token.Or)
                 {
                     _tokenizer.NextToken();
                     IExpressionNode rightNode = ParseRelations();
@@ -84,7 +84,7 @@ namespace VAR.ExpressionEvaluator
                     IExpressionNode rightNode = ParsePlusAndMinus();
                     leftNode = new ExpressionEqualsNode(leftNode, rightNode);
                 }
-                if (_tokenizer.Token == Token.ExclusiveEquals)
+                else if (_tokenizer.Token == Token.ExclusiveEquals)
                 {
                     // TODO: Implement ExpressionExclusiveEqualsNode
                     _tokenizer.NextToken();