From 248cad99e3c3a8b55d78087cad1a03645a788ce6 Mon Sep 17 00:00:00 2001
From: Graham <gpe@openrs2.dev>
Date: Wed, 5 Feb 2020 09:21:43 +0000
Subject: [PATCH] Improve safety of IFEQ/IFNE check in
 OpaquePredicateTransformer

---
 .../transform/OpaquePredicateTransformer.kt    | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/deob/src/main/java/dev/openrs2/deob/transform/OpaquePredicateTransformer.kt b/deob/src/main/java/dev/openrs2/deob/transform/OpaquePredicateTransformer.kt
index b833b9f1d8..6084d4f817 100644
--- a/deob/src/main/java/dev/openrs2/deob/transform/OpaquePredicateTransformer.kt
+++ b/deob/src/main/java/dev/openrs2/deob/transform/OpaquePredicateTransformer.kt
@@ -88,13 +88,17 @@ class OpaquePredicateTransformer : Transformer() {
         // find and fix opaque predicates
         for (match in OPAQUE_PREDICATE_MATCHER.match(method).filter { isOpaquePredicate(method, it) }) {
             val branch = match[1] as JumpInsnNode
-            if (branch.opcode == Opcodes.IFEQ) {
-                // branch is always taken
-                method.instructions.remove(match[0])
-                branch.opcode = Opcodes.GOTO
-            } else { // IFNE
-                // branch is never taken
-                match.forEach(method.instructions::remove)
+            when (branch.opcode) {
+                Opcodes.IFEQ -> {
+                    // branch is always taken
+                    method.instructions.remove(match[0])
+                    branch.opcode = Opcodes.GOTO
+                }
+                Opcodes.IFNE -> {
+                    // branch is never taken
+                    match.forEach(method.instructions::remove)
+                }
+                else -> error("Invalid opcode")
             }
 
             opaquePredicates++