Fix crash when warner stack is empty

mcimadamore · Aug 22, 2024 · 21af275 · 21af275
1 parent fc76d38
commit 21af275
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java
@@ -1096,7 +1096,7 @@ public boolean isSubtype(Type t, Type s, boolean capture, Warner warner) {
 
     public boolean isSubtype(Type t, Type s, boolean capture) {
         if (t.equalsIgnoreMetadata(s)) {
-            if (enableNullRestrictedTypes && hasNarrowerNullability(s, t)) {
+            if (enableNullRestrictedTypes && warnStack.nonEmpty() && hasNarrowerNullability(s, t)) {
                 warnStack.head.warn(LintCategory.NULL);
             }
             return true;
@@ -1218,7 +1218,7 @@ public Boolean visitClassType(ClassType t, Type s) {
                     && (!s.isParameterized() || containsTypeRecursive(s, sup))
                     && isSubtypeNoCapture(sup.getEnclosingType(),
                                           s.getEnclosingType());
-                if (result && enableNullRestrictedTypes && hasNarrowerNullability(s, t)) {
+                if (result && enableNullRestrictedTypes && warnStack.nonEmpty() && hasNarrowerNullability(s, t)) {
                     warnStack.head.warn(LintCategory.NULL);
                 }
                 return result;
@@ -1452,7 +1452,7 @@ public Boolean visitClassType(ClassType t, Type s) {
                 boolean equal = t.tsym == s.tsym
                         && visit(t.getEnclosingType(), s.getEnclosingType())
                         && containsTypeEquivalent(t.getTypeArguments(), s.getTypeArguments());
-                if (equal && enableNullRestrictedTypes && !hasSameNullability(s, t)) {
+                if (equal && enableNullRestrictedTypes && warnStack.nonEmpty() && !hasSameNullability(s, t)) {
                     warnStack.head.warn(LintCategory.NULL);
                 }
                 return equal;