From 8a226b3139ddd37328640fda2377a9270050802b Mon Sep 17 00:00:00 2001
From: NovaRain <novarain@gmail.com>
Date: Tue, 8 Jun 2021 07:07:27 +0800
Subject: [PATCH] Fixed infinite loop in combat with AIDrugUsePerfFix

---
 sfall/BugFixes.cpp  | 15 ++++++++-------
 sfall/ddraw.vcxproj |  4 ++--
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/sfall/BugFixes.cpp b/sfall/BugFixes.cpp
index a69358e7..aee57940 100644
--- a/sfall/BugFixes.cpp
+++ b/sfall/BugFixes.cpp
@@ -1998,35 +1998,36 @@ skip:
 
 static DWORD firstItemDrug = -1;
 
+// when there are no more items in the inventory
 static void __declspec(naked) ai_check_drugs_hack_break() {
 	static const DWORD ai_check_drugs_hack_Ret = 0x42878B;
 	__asm {
 		mov  eax, -1;
 		cmp  firstItemDrug, eax;
-		jne  firstDrugs;                   // pid != -1
+		jne  useDrugs;                     // pid != -1
 		add  esp, 4;
 		jmp  ai_check_drugs_hack_Ret;      // break loop
-firstDrugs:
+useDrugs: // use the first found item
 		mov  dword ptr [esp + 4], eax;     // slot set -1
 		mov  edi, firstItemDrug;
 		mov  ebx, edi;
 		mov  firstItemDrug, eax;           // set -1
-		retn;                              // use drug
+		retn;                              // goto check (use drug)
 	}
 }
 
 static void __declspec(naked) ai_check_drugs_hack_check() {
 	__asm {
-		test [esp + 0x34 - 0x30 + 4], 0;   // check NoInvenItem != 0
-		jnz  skip;
+		test [esp + 0x34 - 0x30 + 4], 1;   // check NoInvenItem != 0
+		jnz  skip;                         // there are no more drugs in inventory
 		cmp  dword ptr [edx + 0xAC], -1;   // cap.chem_primary_desire (Chemical Preference Number)
 		jnz  checkDrugs;
 skip:
 		xor  ebx, ebx;                     // set ZF for skipping preference list check
 		retn;
 checkDrugs:
-		cmp  ebx, [edx + 0xAC];            // check item.pid against cap.chem_primary_desire
-		retn;
+		cmp  ebx, [edx + 0xAC];            // item.pid == cap.chem_primary_desire?
+		retn;                              // if yes, use it (jz 0x4286C7); otherwise, check the other values of chem_primary_desire
 	}
 }
 
diff --git a/sfall/ddraw.vcxproj b/sfall/ddraw.vcxproj
index f6632b42..2e153eec 100644
--- a/sfall/ddraw.vcxproj
+++ b/sfall/ddraw.vcxproj
@@ -82,7 +82,7 @@
     <Link>
       <AdditionalDependencies>d3d9.lib;d3dx9.lib;dinput.lib;Strmiids.lib;ws2_32.lib;%(AdditionalDependencies)</AdditionalDependencies>
       <ModuleDefinitionFile>exports.def</ModuleDefinitionFile>
-      <DelayLoadDLLs>ws2_32.dll;d3d9.dll;d3dx9d_43.dll;%(DelayLoadDLLs)</DelayLoadDLLs>
+      <DelayLoadDLLs>ws2_32.dll;d3d9.dll;d3dx9d_42.dll;%(DelayLoadDLLs)</DelayLoadDLLs>
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <SubSystem>Console</SubSystem>
       <OptimizeReferences>false</OptimizeReferences>
@@ -147,8 +147,8 @@
       </DataExecutionPrevention>
       <TargetMachine>MachineX86</TargetMachine>
       <ImageHasSafeExceptionHandlers>false</ImageHasSafeExceptionHandlers>
-      <MinimumRequiredVersion>5.00</MinimumRequiredVersion>
       <AdditionalLibraryDirectories>$(DXSDK_DIR)lib\x86\</AdditionalLibraryDirectories>
+      <MinimumRequiredVersion>5.00</MinimumRequiredVersion>
     </Link>
     <PostBuildEvent>
       <Command>"$(ProjectDir)postbuild.cmd" release "$(TargetPath)"</Command>