From 3a5bedf702e66b53654da57e945516f39866abfe Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Tue, 4 Feb 2014 20:19:13 -0600
Subject: [PATCH] Fix constant || and && evaluation

- When SendExprCommand() evaluates constant expressions for || and &&,
  it must explicitly pop both operands off the stack before pushing the
  result. The compiler will do normal short-circuiting here, so if it only
  needs one value to determine the result, only one would be popped off
  the stack.
---
 parse.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/parse.c b/parse.c
index d04ad5c..e6d63f0 100644
--- a/parse.c
+++ b/parse.c
@@ -3771,7 +3771,7 @@ static void ConstExprFactor(void)
 
 static void SendExprCommand(pcd_t pcd)
 {
-	int operand2;
+	int operand1, operand2;
 
 	if(ConstantExpression == NO)
 	{
@@ -3821,10 +3821,14 @@ static void SendExprCommand(pcd_t pcd)
 			PushExStk(PopExStk() < operand2);
 			break;
 		case PCD_ANDLOGICAL:
-			PushExStk(PopExStk() && PopExStk());
+			operand2 = PopExStk();
+			operand1 = PopExStk();
+			PushExStk(operand1 && operand2);
 			break;
 		case PCD_ORLOGICAL:
-			PushExStk(PopExStk() || PopExStk());
+			operand2 = PopExStk();
+			operand1 = PopExStk();
+			PushExStk(operand1 || operand2);
 			break;
 		case PCD_ANDBITWISE:
 			PushExStk(PopExStk()&PopExStk());