From 842371bdd849a34586dfee0cbb81fbe8728b2cc1 Mon Sep 17 00:00:00 2001
From: coehlrich <coehlrich@users.noreply.github.com>
Date: Sun, 25 Aug 2024 06:21:35 +1200
Subject: [PATCH] Fix lambdas in anonymous classes referencing parameters from
 the root method (#423)

* Fix lambdas in anonymous classes referencing parameters from the root
method

* Update test
---
 .../decompiler/vars/VarDefinitionHelper.java  |  2 +-
 .../java/decompiler/SingleClassesTest.java    |  1 +
 .../pkg/TestAnonymousClassToLambda.dec        | 38 +++++++++++++++++++
 .../java8/pkg/TestAnonymousClassToLambda.java | 11 ++++++
 4 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 testData/results/pkg/TestAnonymousClassToLambda.dec
 create mode 100644 testData/src/java8/pkg/TestAnonymousClassToLambda.java

diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/vars/VarDefinitionHelper.java b/src/org/jetbrains/java/decompiler/modules/decompiler/vars/VarDefinitionHelper.java
index 70ce79b26a..43bdb90ce6 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/vars/VarDefinitionHelper.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/vars/VarDefinitionHelper.java
@@ -1636,7 +1636,7 @@ private void iterateClashingExprent(Statement stat, StructMethod mt, Map<Stateme
           for (String mthKey : node.getWrapper().getMethods().getLstKeys()) {
             MethodWrapper mw = node.getWrapper().getMethods().getWithKey(mthKey);
             StructMethod mt2 = node.getWrapper().getClassStruct().getMethod(mthKey);
-            if (mt2 != null && mw != null) {
+            if (mt2 != null && mw != null && !mt2.hasModifier(CodeConstants.ACC_SYNTHETIC)) {
               // Propagate current data through to method
               VarDefinitionHelper vardef = new VarDefinitionHelper(mw.root, mt2, mw.varproc, false);
 
diff --git a/test/org/jetbrains/java/decompiler/SingleClassesTest.java b/test/org/jetbrains/java/decompiler/SingleClassesTest.java
index bbe5158495..2ab7b5497d 100644
--- a/test/org/jetbrains/java/decompiler/SingleClassesTest.java
+++ b/test/org/jetbrains/java/decompiler/SingleClassesTest.java
@@ -710,6 +710,7 @@ private void registerDefault() {
     register(JAVA_21, "TestSwitchPatternMatchingJ21");
     register(JAVA_21, "TestCastIntersectionJ21");
     register(JAVA_16, "TestRecordLocal");
+    register(JAVA_8, "TestAnonymousClassToLambda");
   }
 
   private void registerEntireClassPath() {
diff --git a/testData/results/pkg/TestAnonymousClassToLambda.dec b/testData/results/pkg/TestAnonymousClassToLambda.dec
new file mode 100644
index 0000000000..6ed994177e
--- /dev/null
+++ b/testData/results/pkg/TestAnonymousClassToLambda.dec
@@ -0,0 +1,38 @@
+package pkg;
+
+public class TestAnonymousClassToLambda {
+   public Object test1(final Object o) {
+      return new Object() {// 5
+         public Runnable getRunnable() {
+            return () -> System.out.println(o);// 7
+         }
+      };
+   }
+}
+
+class 'pkg/TestAnonymousClassToLambda' {
+   method 'test1 (Ljava/lang/Object;)Ljava/lang/Object;' {
+      9      4
+   }
+}
+
+class 'pkg/TestAnonymousClassToLambda$1' {
+   method 'getRunnable ()Ljava/lang/Runnable;' {
+      9      6
+   }
+
+   method 'lambda$getRunnable$0 (Ljava/lang/Object;)V' {
+      0      6
+      1      6
+      2      6
+      3      6
+      4      6
+      5      6
+      6      6
+      7      6
+   }
+}
+
+Lines mapping:
+5 <-> 5
+7 <-> 7
diff --git a/testData/src/java8/pkg/TestAnonymousClassToLambda.java b/testData/src/java8/pkg/TestAnonymousClassToLambda.java
new file mode 100644
index 0000000000..1297464cde
--- /dev/null
+++ b/testData/src/java8/pkg/TestAnonymousClassToLambda.java
@@ -0,0 +1,11 @@
+package pkg;
+
+public class TestAnonymousClassToLambda {
+  public Object test1(Object o) {
+    return new Object() {
+      public Runnable getRunnable() {
+        return () -> System.out.println(o);
+      }
+    };
+  }
+}