From b84451659983271130305809b678f3f2cb4f9e88 Mon Sep 17 00:00:00 2001
From: Flavio Soibelmann Glock <fglock@gmail.com>
Date: Wed, 25 Feb 2026 13:33:33 +0100
Subject: [PATCH] Fix wantarray in eval STRING: pass outer context to apply()

---
 .../perlonjava/backend/bytecode/EvalStringHandler.java    | 8 ++++++--
 .../perlonjava/backend/bytecode/SlowOpcodeHandler.java    | 8 +++++++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/main/java/org/perlonjava/backend/bytecode/EvalStringHandler.java b/src/main/java/org/perlonjava/backend/bytecode/EvalStringHandler.java
index 13db3320e..065258fa4 100644
--- a/src/main/java/org/perlonjava/backend/bytecode/EvalStringHandler.java
+++ b/src/main/java/org/perlonjava/backend/bytecode/EvalStringHandler.java
@@ -43,13 +43,15 @@ public class EvalStringHandler {
      * @param registers     Current register array (for variable access)
      * @param sourceName    Source name for error messages
      * @param sourceLine    Source line for error messages
+     * @param callContext   The calling context (VOID/SCALAR/LIST) for wantarray inside eval
      * @return RuntimeScalar result of evaluation (undef on error)
      */
     public static RuntimeScalar evalString(String perlCode,
                                           InterpretedCode currentCode,
                                           RuntimeBase[] registers,
                                           String sourceName,
-                                          int sourceLine) {
+                                          int sourceLine,
+                                          int callContext) {
         try {
             // Step 1: Clear $@ at start of eval
             GlobalVariable.getGlobalVariable("main::@").set("");
@@ -196,8 +198,10 @@ public static RuntimeScalar evalString(String perlCode,
             }
 
             // Step 6: Execute the compiled code
+            // Use the true outer call context so wantarray() inside the eval body
+            // returns the correct value (undef for void, false for scalar, true for list).
             RuntimeArray args = new RuntimeArray();  // Empty @_
-            RuntimeList result = evalCode.apply(args, RuntimeContextType.SCALAR);
+            RuntimeList result = evalCode.apply(args, callContext);
 
             // Step 7: Return scalar result
             return result.scalar();
diff --git a/src/main/java/org/perlonjava/backend/bytecode/SlowOpcodeHandler.java b/src/main/java/org/perlonjava/backend/bytecode/SlowOpcodeHandler.java
index 09eb9aac0..37c82cb41 100644
--- a/src/main/java/org/perlonjava/backend/bytecode/SlowOpcodeHandler.java
+++ b/src/main/java/org/perlonjava/backend/bytecode/SlowOpcodeHandler.java
@@ -252,13 +252,19 @@ public static int executeEvalString(
         }
         String perlCode = codeScalar.toString();
 
+        // Read outer wantarray from register 2 (set by BytecodeInterpreter from the call site context).
+        // This is the true calling context (VOID/SCALAR/LIST) that wantarray() inside the
+        // eval body must reflect — exactly as evalStringWithInterpreter receives callContext.
+        int callContext = ((RuntimeScalar) registers[2]).getInt();
+
         // Call EvalStringHandler to parse, compile, and execute
         RuntimeScalar result = EvalStringHandler.evalString(
             perlCode,
             code,           // Current InterpretedCode for context
             registers,      // Current registers for variable access
             code.sourceName,
-            code.sourceLine
+            code.sourceLine,
+            callContext     // True outer context for wantarray inside eval body
         );
 
         registers[rd] = result;