Don't crash on b ? null : null;

typetools · Aug 8, 2024 · 9cb1cf4 · 9cb1cf4
1 parent aeb1eb2
commit 9cb1cf4
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Showing 2 changed files with 14 additions and 1 deletion.
diff --git a/dataflow/src/main/java/org/checkerframework/dataflow/cfg/builder/CFGTranslationPhaseOne.java b/dataflow/src/main/java/org/checkerframework/dataflow/cfg/builder/CFGTranslationPhaseOne.java
@@ -2722,7 +2722,15 @@ public Node visitClass(ClassTree tree, Void p) {
   public Node visitConditionalExpression(ConditionalExpressionTree tree, Void p) {
     // see JLS 15.25
     TypeMirror exprType = TreeUtils.typeOf(tree);
-
+    if (exprType.getKind() == TypeKind.NULL) {
+      // Happens when the 2nd and 3rd operands are both null, i.e. b ? null : null.
+      Tree parent = TreePathUtil.getContextForPolyExpression(getCurrentPath());
+      if (parent != null) {
+        exprType = TreeUtils.typeOf(parent);
+      } else {
+        exprType = TypesUtils.getObjectTypeMirror(env);
+      }
+    }
     Label trueStart = new Label();
     Label falseStart = new Label();
     Label merge = new Label();

diff --git a/framework/tests/all-systems/Issue6743.java b/framework/tests/all-systems/Issue6743.java
@@ -0,0 +1,5 @@
+public class Issue6743 {
+  void foo(boolean b) {
+    Object o = b ? null : null;
+  }
+}