From c6e27e8ecb6269886cf185410b05deb1a2cd2b1e Mon Sep 17 00:00:00 2001
From: sschr15 <steven.sschr15@hotmail.com>
Date: Sat, 31 Aug 2024 14:58:42 -0500
Subject: [PATCH] Don't try/catch, instead don't attempt to read the language
 on non-classes

---
 .../vineflower/ijplugin/VineflowerInvoker.kt  | 38 +++++++++----------
 1 file changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/main/kotlin/org/vineflower/ijplugin/VineflowerInvoker.kt b/src/main/kotlin/org/vineflower/ijplugin/VineflowerInvoker.kt
index 61a74b6..533025c 100644
--- a/src/main/kotlin/org/vineflower/ijplugin/VineflowerInvoker.kt
+++ b/src/main/kotlin/org/vineflower/ijplugin/VineflowerInvoker.kt
@@ -251,30 +251,26 @@ class VineflowerInvoker(classLoader: ClassLoader) {
         private val getCurrentDecompContext = classLoader.loadClass("org.jetbrains.java.decompiler.main.DecompilerContext")
             .getMethod("getCurrentContext")
 
-        fun getLanguage(bytes: ByteArray): String {
-            try {
-                // ensure a decompilation context is available (otherwise the structclass constructor will fail)
-                if (getCurrentDecompContext.invoke(null) == null) {
-                    val empty = emptyMap<Nothing, Nothing>()
-                    val bytecodeProvider = myBytecodeProviderCtor.newInstance(empty)
-                    val resultSaver = myResultSaverCtor.newInstance()
+        fun getLanguage(bytes: ByteArray): String? {
+            if (bytes.take(4) != listOf(0xCA, 0xFE, 0xBA, 0xBE).map { it.toByte() }.toByteArray()) {
+                // Non-class file
+                return null
+            }
 
-                    baseDecompilerCtor.newInstance(bytecodeProvider, resultSaver, empty, myLogger)
-                }
+            // ensure a decompilation context is available (otherwise the structclass constructor will fail)
+            if (getCurrentDecompContext.invoke(null) == null) {
+                val empty = emptyMap<Nothing, Nothing>()
+                val bytecodeProvider = myBytecodeProviderCtor.newInstance(empty)
+                val resultSaver = myResultSaverCtor.newInstance()
 
-                val inputStream = dataInputFullStreamCtor.newInstance(bytes)
-                val structClass = structClassCreate.invoke(null, inputStream, true)
-                val pluginContext = getCurrentPluginContext.invoke(null)
-                val languageSpec = pluginContextGetLanguageSpec.invoke(pluginContext, structClass) ?: return "java"
-                return languageSpecName.get(languageSpec) as String
-            } catch (e: Throwable) {
-                if (e is ControlFlowException) {
-                    throw e
-                }
-
-                LOGGER.warn("Failed to determine language of class file", e)
-                return "java"
+                baseDecompilerCtor.newInstance(bytecodeProvider, resultSaver, empty, myLogger)
             }
+
+            val inputStream = dataInputFullStreamCtor.newInstance(bytes)
+            val structClass = structClassCreate.invoke(null, inputStream, true)
+            val pluginContext = getCurrentPluginContext.invoke(null)
+            val languageSpec = pluginContextGetLanguageSpec.invoke(pluginContext, structClass) ?: return "java"
+            return languageSpecName.get(languageSpec) as String
         }
     }
 }