diff --git a/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/Scanner.java b/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/Scanner.java
index 2760d441ae4..de41e49c285 100644
--- a/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/Scanner.java
+++ b/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/Scanner.java
@@ -190,7 +190,7 @@ enum ScanContext {
 	private VanguardParser vanguardParser;
 	ConflictedParser activeParser = null;
 	private boolean consumingEllipsisAnnotations = false;
-	protected boolean multiCaseLabelComma = false;
+	public boolean multiCaseLabelComma = false;
 
 	public static final int RoundBracket = 0;
 	public static final int SquareBracket = 1;
diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/ResolveTests21.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/ResolveTests21.java
index 9d03aa7b126..c9fc9227128 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/ResolveTests21.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/ResolveTests21.java
@@ -115,4 +115,36 @@ private record FooBar<T>(T object) implements Foo {
 		elements
 	);
 }
+
+// https://github.com/eclipse-jdt/eclipse.jdt.core/issues/3050
+// [code select] Unexpected runtime error while computing a text hover: java.lang.NegativeArraySizeException
+public void testIssue3050() throws JavaModelException {
+	this.wc = getWorkingCopy("/Resolve/src/Hover.java",
+			"""
+			interface Function<T, R> {
+			    R apply(T t);
+			}
+
+			public class Hover {
+
+				void d() {
+					Function<Object, Object> f = d -> 2;
+					switch (f) {
+						case Function<?, ?> s -> {}
+					}
+				}
+			}
+			"""
+			);
+	String str = this.wc.getSource();
+	String selection = "Function";
+	int start = str.lastIndexOf(selection);
+	int length = selection.length();
+	IJavaElement[] elements = this.wc.codeSelect(start, length);
+	assertElementsEqual(
+		"Unexpected elements",
+		"Function [in [Working copy] Hover.java [in <default> [in src [in Resolve]]]]",
+		elements
+	);
+}
 }
diff --git a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/select/SelectionParser.java b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/select/SelectionParser.java
index 643dc8a69cb..5f0453989ac 100644
--- a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/select/SelectionParser.java
+++ b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/select/SelectionParser.java
@@ -1459,14 +1459,16 @@ protected void consumeToken(int token) {
 				pushOnElementStack(K_BETWEEN_CASE_AND_COLONORARROW, this.expressionPtr);
 				break;
 			case TokenNameCOMMA :
-				switch (topKnownElementKind(SELECTION_OR_ASSIST_PARSER)) {
-					// for multi constant case stmt
-					// case MONDAY, FRIDAY
-					// if there's a comma, ignore the previous expression (constant)
-					// Which doesn't matter for the next constant
-					case K_BETWEEN_CASE_AND_COLONORARROW:
-						this.expressionPtr--;
-						this.expressionLengthStack[this.expressionLengthPtr]--;
+				if (this.scanner.multiCaseLabelComma) {
+					switch (topKnownElementKind(SELECTION_OR_ASSIST_PARSER)) {
+						// for multi constant case stmt
+						// case MONDAY, FRIDAY
+						// if there's a comma, ignore the previous expression (constant)
+						// Which doesn't matter for the next constant
+						case K_BETWEEN_CASE_AND_COLONORARROW:
+							this.expressionPtr--;
+							this.expressionLengthStack[this.expressionLengthPtr]--;
+					}
 				}
 				break;
 			case TokenNameARROW: