block null entries in refreshchat

3 files changed, 83 insertions, 1 deletions

diff --git a/build.gradle.kts b/build.gradle.kts
index 7301a73f..1506f7b8 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -83,7 +83,7 @@ dependencies {
         exclude(module = "kotlin-stdlib")
         exclude(module = "kotlinx-coroutines-core")
     }
-    shadowMe("com.github.Skytils:AsmHelper:668d11deb2") {
+    shadowMe("com.github.Skytils:AsmHelper:91ecc2bd9c") {
         exclude(module = "kotlin-reflect")
         exclude(module = "kotlin-stdlib-jdk8")
         exclude(module = "kotlin-stdlib-jdk7")
diff --git a/src/main/kotlin/skytils/skytilsmod/asm/SkytilsTransformer.kt b/src/main/kotlin/skytils/skytilsmod/asm/SkytilsTransformer.kt
index 86b2ecf4..aeffb06c 100644
--- a/src/main/kotlin/skytils/skytilsmod/asm/SkytilsTransformer.kt
+++ b/src/main/kotlin/skytils/skytilsmod/asm/SkytilsTransformer.kt
@@ -50,6 +50,7 @@ class SkytilsTransformer : BaseClassTransformer() {
                 injectSplashProgressTransformer()
                 changeRenderedName()
                 insertReceivePacketEvent()
+                injectNullCheck()
             } catch (e: Throwable) {
                 e.printStackTrace()
             }
diff --git a/src/main/kotlin/skytils/skytilsmod/asm/transformers/GuiNewChatTransformer.kt b/src/main/kotlin/skytils/skytilsmod/asm/transformers/GuiNewChatTransformer.kt
new file mode 100644
index 00000000..b0ff830a
--- /dev/null
+++ b/src/main/kotlin/skytils/skytilsmod/asm/transformers/GuiNewChatTransformer.kt
@@ -0,0 +1,81 @@
+/*
+ * Skytils - Hypixel Skyblock Quality of Life Mod
+ * Copyright (C) 2021 Skytils
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package skytils.skytilsmod.asm.transformers
+
+import dev.falsehonesty.asmhelper.dsl.instructions.InsnListBuilder
+import dev.falsehonesty.asmhelper.dsl.instructions.JumpCondition
+import dev.falsehonesty.asmhelper.dsl.modify
+import org.objectweb.asm.Opcodes
+import org.objectweb.asm.tree.*
+import skytils.skytilsmod.utils.Utils
+
+fun injectNullCheck() = modify("net.minecraft.client.gui.GuiNewChat") {
+    classNode.methods.find {
+        Utils.equalsOneOf(it.name, "refreshChat", "b") && it.desc == "()V"
+    }?.apply {
+        var labelNode: LabelNode? = null
+        var incInsn: VarInsnNode? = null
+        for (insn in instructions) {
+            if (insn is LabelNode) {
+                var prev = insn.previous
+                var valid = true
+                for (i in 1..5) {
+                    if (prev == null || !valid) {
+                        valid = false
+                        break
+                    }
+                    valid = when (i) {
+                        1 -> prev is VarInsnNode && prev.opcode == Opcodes.ISTORE
+                        2 -> prev.opcode == Opcodes.ISUB
+                        3 -> prev.opcode == Opcodes.ICONST_1
+                        4 -> prev is MethodInsnNode && prev.owner == "java/util/List" && prev.name == "size"
+                        5 -> prev is FieldInsnNode && prev.opcode == Opcodes.GETFIELD && Utils.equalsOneOf(
+                            prev.owner,
+                            "net/minecraft/client/gui/GuiNewChat",
+                            "avt"
+                        ) && Utils.equalsOneOf(prev.name, "chatLines", "h") && prev.desc == "Ljava/util/List;"
+                        else -> throw NotImplementedError()
+                    }
+                    prev = prev.previous
+                }
+                if (valid) {
+                    labelNode = insn
+                    incInsn = insn.previous as VarInsnNode
+                }
+            }
+            if (labelNode != null && incInsn != null && insn is VarInsnNode && insn.opcode == Opcodes.ASTORE) {
+                val temp = insn.previous?.previous?.previous?.previous ?: continue
+                if (temp.opcode == Opcodes.GETFIELD && temp is FieldInsnNode && Utils.equalsOneOf(
+                        temp.owner,
+                        "net/minecraft/client/gui/GuiNewChat",
+                        "avt"
+                    ) && Utils.equalsOneOf(temp.name, "chatLines", "h") && temp.desc == "Ljava/util/List;"
+                ) {
+                    instructions.insert(insn, InsnListBuilder(this).apply {
+                        aload(insn.`var`)
+                        ifClause(JumpCondition.NON_NULL) {
+                            insn(IincInsnNode(incInsn.`var`, -1))
+                            jump(JumpCondition.GOTO, labelNode)
+                        }
+                    }.build())
+                }
+            }
+        }
+    }
+}
\ No newline at end of file