Replaced serial single-byte NOPs with long NOPs

(the sequence is 5-byte long NOPs with trailing single-byte NOPs)

sfall/Modules/MiscPatches.cpp

@@ -912,7 +912,7 @@ static void EngineOptimizationPatches() {
 	// Remove redundant/duplicate code
 	BlockCall(0x45EBBF); // intface_redraw_
 	BlockCall(0x4A4859); // exec_script_proc_
-	SafeMemSet(0x455189, CodeType::Nop, 11); // op_create_object_sid_
+	BlockCall(0x455189, 11); // op_create_object_sid_
 
 	// Improve performance of the data conversion of script interpreter
 	// mov eax, [edx+eax]; bswap eax; ret;

sfall/Modules/Scripting/Handlers/Objects.cpp

@@ -52,10 +52,10 @@ static void __cdecl IncNPCLevel(const char* fmt, const char* name) {
 
 		SafeWrite32(0x495C50, 0x01FB840F); // Want to keep this check intact. (restore)
 
-		SafeMemSet(0x495C77, CodeType::Nop, 6);   // Check that the player is high enough for the npc to consider this level
-		//SafeMemSet(0x495C8C, CodeType::Nop, 6); // Check that the npc isn't already at its maximum level
-		SafeMemSet(0x495CE3, CodeType::Nop, 5);   // Check if npc had "early" level up before the next scheduled one, resets the "early" flag
-		SafeMemSet(0x495CEC, CodeType::Nop, 6);   // Related to above
+		BlockCall(0x495C77, 6);   // Check that the player is high enough for the npc to consider this level
+		//BlockCall(0x495C8C, 6); // Check that the npc isn't already at its maximum level
+		BlockCall(0x495CE3);      // Check if npc had "early" level up before the next scheduled one, resets the "early" flag
+		BlockCall(0x495CEC, 6);   // Related to above
 		SafeWrite8(0x495CFB, CodeType::JumpShort); // Skip random roll for early level up
 		__asm mov dword ptr [ebp + 0x150 - 0x28 + 16], 255; // set counter for exit loop
 	} else {

sfall/Modules/Worldmap.cpp

@@ -410,8 +410,8 @@ static void TimeLimitPatch() {
 				0x4A3547  // inc_game_time_in_seconds_
 			};
 			MakeCalls(TimerReset, timerResetAddr);
-			SafeMemSet(0x4A34F4, CodeType::Nop, 16);
-			SafeMemSet(0x4A354C, CodeType::Nop, 16);
+			BlockCall(0x4A34F4, 16);
+			BlockCall(0x4A354C, 16);
 		} else {
 			SafeWrite8(0x4A34EC, limit);
 			SafeWrite8(0x4A3544, limit);

sfall/SafeWrite.cpp

@@ -101,8 +101,30 @@ void BlockCall(DWORD addr) {
 	DWORD oldProtect;
 
 	VirtualProtect((void*)addr, 4, PAGE_EXECUTE_READWRITE, &oldProtect);
-	*((DWORD*)addr) = 0x00441F0F; // long NOP (0F1F4400-XX)
+	*((DWORD*)addr) = 0x00441F0F; // 5-byte long NOP (0F1F4400-XX)
 	VirtualProtect((void*)addr, 4, oldProtect, &oldProtect);
 }
 
+static __declspec(noinline) void __stdcall SafeWriteNops(DWORD addr, size_t len) {
+	DWORD oldProtect;
+
+	VirtualProtect((void*)addr, len, PAGE_EXECUTE_READWRITE, &oldProtect);
+	DWORD cur = addr, remaining = len;
+	while (remaining >= 5) {
+		*((DWORD*)cur) = 0x00441F0F; // 5-byte long NOP (0F1F4400-XX)
+		cur += 5;
+		remaining -= 5;
+	}
+	// Fill the remaining bytes (1-4 bytes) with single-byte NOPs
+	while (remaining > 0) {
+		*((BYTE*)cur++) = CodeType::Nop;
+		remaining--;
+	}
+	VirtualProtect((void*)addr, len, oldProtect, &oldProtect);
+}
+
+void BlockCall(DWORD addr, size_t len) {
+	SafeWriteNops(addr, len);
+}
+
 }

sfall/SafeWrite.h

@@ -52,6 +52,8 @@ void MakeCall(DWORD addr, void* func, size_t len);
 void MakeJump(DWORD addr, void* func);
 void MakeJump(DWORD addr, void* func, size_t len);
 void BlockCall(DWORD addr);
+// Should be used for patching out 6+ bytes (use single-byte NOPs for 1-4 bytes)
+void BlockCall(DWORD addr, size_t len);
 
 // emulation of 4.x HookCalls/MakeCalls/MakeJumps