Fix for bug #2016647 (FW: crash with italian amiga version).

- Consists of a workaround for a script bug that used local
  variable 251 when it should've used global variable 251.
- Also added a fix for a crash when failing copy protection
  in Amiga or Atari ST versions of Future Wars.
NOTE: That any of the Amiga or Atari ST versions of Future Wars
haven't crashed right in the beginning before seems like plain
luck because accessing local variable 251 is out of bounds!

svn-id: r33068

5 files changed, 34 insertions, 6 deletions

diff --git a/engines/cine/cine.h b/engines/cine/cine.h
index 710840c17e..7568d8310e 100644
--- a/engines/cine/cine.h
+++ b/engines/cine/cine.h
@@ -107,6 +107,7 @@ private:
 extern CineEngine *g_cine;
 
 #define BOOT_PRC_NAME "AUTO00.PRC"
+#define COPY_PROT_FAIL_PRC_NAME "L201.ANI"
 
 enum {
 	VAR_MOUSE_X_MODE = 253,
diff --git a/engines/cine/prc.cpp b/engines/cine/prc.cpp
index 402c97b1a6..27b1044620 100644
--- a/engines/cine/prc.cpp
+++ b/engines/cine/prc.cpp
@@ -40,8 +40,9 @@ ScriptList objectScripts;
 
 /*! \todo Is script size of 0 valid?
  * \todo Fix script dump code
+ * @return Was the loading successful?
  */
-void loadPrc(const char *pPrcName) {
+bool loadPrc(const char *pPrcName) {
 	byte i;
 	uint16 numScripts;
 	byte *scriptPtr, *dataPtr;
@@ -52,9 +53,9 @@ void loadPrc(const char *pPrcName) {
 	scriptTable.clear();
 
 	// This is copy protection. Used to hang the machine
-	if (!scumm_stricmp(pPrcName, "L201.ANI")) {
+	if (!scumm_stricmp(pPrcName, COPY_PROT_FAIL_PRC_NAME)) {
 		exitEngine = 1;
-		return;
+		return false;
 	}
 
 	checkDataDisk(-1);
@@ -107,6 +108,8 @@ void loadPrc(const char *pPrcName) {
 		}
 	}
 #endif
+
+	return true;
 }
 
 } // End of namespace Cine
diff --git a/engines/cine/prc.h b/engines/cine/prc.h
index f5129d28b1..05bb240372 100644
--- a/engines/cine/prc.h
+++ b/engines/cine/prc.h
@@ -31,7 +31,7 @@ namespace Cine {
 extern ScriptList globalScripts;
 extern ScriptList objectScripts;
 
-void loadPrc(const char *pPrcName);
+bool loadPrc(const char *pPrcName);
 
 } // End of namespace Cine
 
diff --git a/engines/cine/script_fw.cpp b/engines/cine/script_fw.cpp
index 148e673095..54a4976000 100644
--- a/engines/cine/script_fw.cpp
+++ b/engines/cine/script_fw.cpp
@@ -1019,6 +1019,20 @@ int FWScript::o1_divVar() {
 }
 
 int FWScript::o1_compareVar() {
+	// WORKAROUND: A workaround for a script bug in script file CODE2.PRC
+	// in at least some of the Amiga and Atari ST versions of Future Wars.
+	// Fixes bug #2016647 (FW: crash with italian amiga version). A local
+	// variable 251 is compared against value 0 although it's quite apparent
+	// from the context in the script that instead global variable 251 should
+	// be compared against value 0. So looks like someone made a typo when
+	// making the scripts. Therefore we change that particular comparison
+	// from using the local variable 251 to using the global variable 251.
+	if (g_cine->getGameType() == Cine::GType_FW && scumm_stricmp(currentPrcName, "CODE2.PRC") == 0 &&
+		(g_cine->getPlatform() == Common::kPlatformAmiga || g_cine->getPlatform() == Common::kPlatformAtariST) &&
+		_script.getByte(_pos) == 251 && _script.getByte(_pos + 1) == 0 && _script.getWord(_pos + 2) == 0) {
+		return o1_compareGlobalVar();
+	}
+
 	byte varIdx = getNextByte();
 	byte varType = getNextByte();
 
diff --git a/engines/cine/various.cpp b/engines/cine/various.cpp
index 4b5d4efe13..69851aeff2 100644
--- a/engines/cine/various.cpp
+++ b/engines/cine/various.cpp
@@ -1518,12 +1518,22 @@ void mainLoopSub6(void) {
 
 void checkForPendingDataLoad(void) {
 	if (newPrcName[0] != 0) {
-		loadPrc(newPrcName);
+		bool loadPrcOk = loadPrc(newPrcName);
 
 		strcpy(currentPrcName, newPrcName);
 		strcpy(newPrcName, "");
 
-		addScriptToList0(1);
+		// Check that the loading of the script file was successful before
+		// trying to add script 1 from it to the global scripts list. This
+		// fixes a crash when failing copy protection in Amiga or Atari ST
+		// versions of Future Wars.
+		if (loadPrcOk) {
+			addScriptToList0(1);
+		} else if (scumm_stricmp(currentPrcName, COPY_PROT_FAIL_PRC_NAME)) {
+			// We only show an error here for other files than the file that
+			// is loaded if copy protection fails (i.e. L201.ANI).
+			warning("checkForPendingDataLoad: loadPrc(%s) failed", currentPrcName);
+		}
 	}
 
 	if (newRelName[0] != 0) {