From 594d27ce7e7780686fcd0bbed2d08349c8d2d82b Mon Sep 17 00:00:00 2001
From: Karl-Erik Enkelmann <playdohface@gmail.com>
Date: Sat, 18 Oct 2025 10:26:48 +0200
Subject: [PATCH] Handle unavailable sources in compliance with DAP spec

---
 .../debug/core/adapter/handler/StackTraceRequestHandler.java  | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/StackTraceRequestHandler.java b/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/StackTraceRequestHandler.java
index 49f30477..3fa0a9a9 100644
--- a/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/StackTraceRequestHandler.java
+++ b/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/StackTraceRequestHandler.java
@@ -220,8 +220,10 @@ private Types.StackFrame convertDebuggerStackFrameToClient(StackFrameInfo jdiFra
             } else {
                 // For other unavailable method, such as lambda expression's built-in methods run/accept/apply,
                 // display "Unknown Source" in the Call Stack View.
-                clientSource = null;
+                clientSource = new Types.Source("Unknown Source", "unknown", 0);
             }
+            // DAP specifies lineNumber to be set to 0 when unavailable
+            clientLineNumber = 0;
         } else if (DebugSettings.getCurrent().debugSupportOnDecompiledSource == Switch.ON
                 && clientSource != null && clientSource.path != null) {
             // Align the original line with the decompiled line.