From 2022d64ee2a39be538b029dd3da1d121d5d1a942 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Fri, 21 Dec 2012 22:47:55 +0000
Subject: [PATCH] - Do not crash when reading ATAG chunks on processors that
 don't like unaligned accesses.

SVN r3991 (trunk)
---
 src/p_acs.cpp | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 437a9cfe8a..ead7b198aa 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -173,6 +173,27 @@ TArray<FString>
 #define STRINGBUILDER_START(Builder) if (Builder.IsNotEmpty() || ACS_StringBuilderStack.Size()) { ACS_StringBuilderStack.Push(Builder); Builder = ""; }
 #define STRINGBUILDER_FINISH(Builder) if (!ACS_StringBuilderStack.Pop(Builder)) { Builder = ""; }
 
+//============================================================================
+//
+// uallong
+//
+// Read a possibly unaligned four-byte little endian integer from memory.
+//
+//============================================================================
+
+#if defined(_M_IX86) || defined(_M_X64) || defined(__i386__)
+inline int uallong(const int &foo)
+{
+	return foo;
+}
+#else
+inline int uallong(const int &foo)
+{
+	const unsigned char *bar = (const unsigned char *)&foo;
+	return bar[0] | (bar[1] << 8) | (bar[2] << 16) | (bar[3] << 24);
+}
+#endif
+
 //============================================================================
 //
 // ScriptPresentation
@@ -1259,7 +1280,7 @@ FBehavior::FBehavior (int lumpnum, FileReader * fr, int len)
 				// First byte is version, it should be 0
 				if(*chunkData++ == 0)
 				{
-					int arraynum = MapVarStore[LittleLong(*(const DWORD*)(chunkData))];
+					int arraynum = MapVarStore[uallong(*(const int*)(chunkData))];
 					chunkData += 4;
 					if ((unsigned)arraynum < (unsigned)NumArrays)
 					{
@@ -4010,20 +4031,6 @@ inline int getshort (int *&pc)
 	return res;
 }
 
-// Read a possibly unaligned four-byte little endian integer.
-#if defined(_M_IX86) || defined(_M_X64) || defined(__i386__) 
-inline int uallong(int &foo)
-{
-	return foo;
-}
-#else
-inline int uallong(int &foo)
-{
-	unsigned char *bar = (unsigned char *)&foo;
-	return bar[0] | (bar[1] << 8) | (bar[2] << 16) | (bar[3] << 24);
-}
-#endif
-
 int DLevelScript::RunScript ()
 {
 	DACSThinker *controller = DACSThinker::ActiveThinker;