Fix wrong variable reference in debug tooltip for inherited methods

Add check to confirm the field's declaring type is an ancestor of this's
runtime type

Fixes : #396

Author: SougandhS

org.eclipse.jdt.debug.tests/java8/Element.java

@@ -0,0 +1,40 @@
+/*******************************************************************************
+ * Copyright (c) 2026 IBM Corporation.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+public class Element {
+
+	public Element element;
+
+	public Element() {
+	}
+
+	public Element(Element element) {
+		this.element = element;
+	}
+
+	public void iterateElements() {
+		System.out.println(element); 
+		if (element != null) {
+			element.iterateElements();
+		}
+	}
+	
+	@Override
+	public String toString() {
+		return getClass().getSimpleName();
+	}
+	public static void main(String[] args) {
+		Element root = new Element(new SubElement(new Element()));
+		root.iterateElements();
+	}
+}

org.eclipse.jdt.debug.tests/java8/SubElement.java

@@ -0,0 +1,19 @@
+/*******************************************************************************
+ * Copyright (c) 2026 IBM Corporation.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+public class SubElement extends Element {
+
+	public SubElement(Element element) {
+		super(element);
+	}
+}

org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/AbstractDebugTest.java

@@ -556,6 +556,8 @@ synchronized void assert18Project() {
 				cfgs.add(createLaunchConfiguration(jp, "InnerClassBug"));
 				cfgs.add(createLaunchConfiguration(jp, "SuperClass"));
 				cfgs.add(createLaunchConfiguration(jp, "SubClass"));
+				cfgs.add(createLaunchConfiguration(jp, "Element"));
+				cfgs.add(createLaunchConfiguration(jp, "SubElement"));
 	    		loaded18 = true;
 	    		waitForBuild();
 	        }

org.eclipse.jdt.debug.tests/tests/org/eclipse/jdt/debug/tests/ui/DebugHoverTests.java

@@ -438,6 +438,7 @@ public void testBug572629_ChainFieldHover_ArrayLengthChainsOnVariableThisExpress
 			removeAllBreakpoints();
 		}
 	}
+
 	public void testBug572629_ChainFieldHover_3Chains_ExpectValueFromChainAtMiddle() throws Exception {
 		sync(() -> TestUtil.waitForJobs(getName(), 1000, 10000, ProcessConsole.class));
 
@@ -1594,4 +1595,42 @@ public void testResolveSameFieldsInSuperAndSub() throws Exception {
 		}
 	}
 
+	public void testResolveFieldOnInheritedMethodFrame() throws Exception {
+		sync(() -> TestUtil.waitForJobs(getName(), 1000, 10000, ProcessConsole.class));
+
+		final String typeName = "Element";
+		final String expectedMethod = "iterateElements";
+		final int framesNumber = 2;
+		final int bpLine1 = 26;
+
+		IJavaBreakpoint bp1 = createLineBreakpoint(bpLine1, "", typeName + ".java", typeName);
+		bp1.setSuspendPolicy(IJavaBreakpoint.SUSPEND_THREAD);
+		IFile file = (IFile) bp1.getMarker().getResource();
+		assertEquals(typeName + ".java", file.getName());
+		IJavaThread thread = null;
+		try {
+			thread = launchToBreakpoint(typeName);
+			CompilationUnitEditor part = openEditorAndValidateStack(expectedMethod, framesNumber, file, thread);
+			JavaDebugHover hover = new JavaDebugHover();
+			hover.setEditor(part);
+			int offset = part.getViewer().getDocument().get().indexOf("element);");
+			String variableName = "element";
+			IRegion region = new Region(offset, variableName.length());
+			String text = selectAndReveal(part, bpLine1, region);
+			assertEquals(variableName, text);
+			IVariable info = (IVariable) sync(() -> hover.getHoverInfo2(part.getViewer(), region));
+			assertNotNull(info);
+			String hoverVal = info.getValue().toString();
+			assertTrue(hoverVal.contains("SubElement"));
+			thread = resume(thread);
+			info = (IVariable) sync(() -> hover.getHoverInfo2(part.getViewer(), region));
+			assertNotNull(info);
+			hoverVal = info.getValue().toString();
+			assertTrue(hoverVal.contains("Element"));
+		} finally {
+			terminateAndRemove(thread);
+			removeAllBreakpoints();
+		}
+	}
+
 }

org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/JavaDebugHover.java

@@ -52,6 +52,7 @@
 import org.eclipse.jdt.core.dom.StructuralPropertyDescriptor;
 import org.eclipse.jdt.core.dom.ThisExpression;
 import org.eclipse.jdt.core.manipulation.SharedASTProviderCore;
+import org.eclipse.jdt.debug.core.IJavaClassType;
 import org.eclipse.jdt.debug.core.IJavaDebugTarget;
 import org.eclipse.jdt.debug.core.IJavaObject;
 import org.eclipse.jdt.debug.core.IJavaReferenceType;
@@ -650,7 +651,7 @@ private static Predicate<IJavaStackFrame> forLocalVariable(ILocalVariable variab
 	private static Predicate<IJavaStackFrame> forField(IField field) {
 		return frame -> {
 			try {
-				return frame.getThis() != null && frame.getThis().getJavaType().getName().equals(field.getDeclaringType().getFullyQualifiedName())
+				return frame.getThis() != null && isInstanceOfDeclaringType(frame.getThis(), field)
 						&& containsVariable(frame, field.getElementName());
 			} catch (DebugException e) {
 				JDIDebugUIPlugin.log(e);
@@ -660,4 +661,16 @@ private static Predicate<IJavaStackFrame> forField(IField field) {
 
 	}
 
+	private static boolean isInstanceOfDeclaringType(IJavaObject javaObject, IField field) throws DebugException {
+		String declaringTypeName = field.getDeclaringType().getFullyQualifiedName();
+		IJavaType type = javaObject.getJavaType();
+		while (type instanceof IJavaClassType classType) {
+			if (declaringTypeName.equals(classType.getName())) {
+				return true;
+			}
+			type = classType.getSuperclass();
+		}
+		return false;
+	}
+
 }