From 8d1bb5f3d9da544cf6e3e3848bfcc56327cde810 Mon Sep 17 00:00:00 2001
From: Lucaskyy <contact@sculas.xyz>
Date: Thu, 24 Mar 2022 20:58:10 +0100
Subject: [PATCH] fix(MethodResolver): strip labels and line numbers so opcode
 patterns match

---
 .../patcher/resolver/MethodResolver.kt        | 20 +++++++++----------
 .../app/revanced/patcher/util/TestUtil.kt     |  3 ++-
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/src/main/kotlin/app/revanced/patcher/resolver/MethodResolver.kt b/src/main/kotlin/app/revanced/patcher/resolver/MethodResolver.kt
index c27a3fd..187d985 100644
--- a/src/main/kotlin/app/revanced/patcher/resolver/MethodResolver.kt
+++ b/src/main/kotlin/app/revanced/patcher/resolver/MethodResolver.kt
@@ -7,9 +7,7 @@ import app.revanced.patcher.cache.PatternScanData
 import app.revanced.patcher.signature.Signature
 import app.revanced.patcher.util.ExtraTypes
 import org.objectweb.asm.Type
-import org.objectweb.asm.tree.ClassNode
-import org.objectweb.asm.tree.InsnList
-import org.objectweb.asm.tree.MethodNode
+import org.objectweb.asm.tree.*
 
 private val logger = KotlinLogging.logger("MethodResolver")
 
@@ -110,7 +108,7 @@ internal class MethodResolver(private val classList: List<ClassNode>, private va
             }
 
             signature.opcodes?.let { _ ->
-                val result = method.instructions.scanFor(signature.opcodes)
+                val result = method.instructions.stripLabels().scanFor(signature.opcodes)
                 if (!result.found) {
                     logger.debug { "Comparing sig ${signature.name}: invalid opcode pattern" }
                     return@cmp false to null
@@ -123,13 +121,8 @@ internal class MethodResolver(private val classList: List<ClassNode>, private va
     }
 }
 
-private operator fun ClassNode.component1(): ClassNode {
-    return this
-}
-
-private operator fun ClassNode.component2(): List<MethodNode> {
-    return this.methods
-}
+private operator fun ClassNode.component1() = this
+private operator fun ClassNode.component2() = this.methods
 
 private fun InsnList.scanFor(pattern: IntArray): ScanResult {
     for (i in 0 until this.size()) {
@@ -157,3 +150,8 @@ private fun Type.convertObject(): Type {
 private fun Array<Type>.convertObjects(): Array<Type> {
     return this.map { it.convertObject() }.toTypedArray()
 }
+
+private fun InsnList.stripLabels(): InsnList {
+    this.removeAll { it is LabelNode || it is LineNumberNode }
+    return this
+}
diff --git a/src/test/kotlin/app/revanced/patcher/util/TestUtil.kt b/src/test/kotlin/app/revanced/patcher/util/TestUtil.kt
index de9c831..6d891e1 100644
--- a/src/test/kotlin/app/revanced/patcher/util/TestUtil.kt
+++ b/src/test/kotlin/app/revanced/patcher/util/TestUtil.kt
@@ -38,7 +38,8 @@ private class NodeStringBuilder {
     }
 
     override fun toString(): String {
+        if (sb.isEmpty()) return ""
         val s = sb.toString()
-        return s.substring(0 until s.length - 2) // remove the last ", "
+        return s.substring(0 .. (s.length - 2).coerceAtLeast(0)) // remove the last ", "
     }
 }