(groovy) branch master updated: GROOVY-11815: STC: retain generics of LUB under an `instanceof` guard

[emilles]

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emilles pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/groovy.git


The following commit(s) were added to refs/heads/master by this push:
     new cc8bc3e408 GROOVY-11815: STC: retain generics of LUB under an 
`instanceof` guard
cc8bc3e408 is described below

commit cc8bc3e408f5bc7a6779c70f11a29a4cffdf04a8
Author: Eric Milles <eric.mil...@thomsonreuters.com>
AuthorDate: Mon Dec 8 10:48:57 2025 -0600

    GROOVY-11815: STC: retain generics of LUB under an `instanceof` guard
---
 .../transform/stc/StaticTypeCheckingVisitor.java    |  2 +-
 .../transform/stc/TypeInferenceSTCTest.groovy       | 21 ++++++++++++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git 
a/src/main/java/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java
 
b/src/main/java/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java
index 2e63acbe50..bf4451ecae 100644
--- 
a/src/main/java/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java
+++ 
b/src/main/java/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java
@@ -6215,7 +6215,7 @@ out:    for (ClassNode type : todo) {
                 ClassNode   superclass;
                 ClassNode[] interfaces;
                 if (expressionType instanceof 
WideningCategories.LowestUpperBoundClassNode) {
-                    superclass = expressionType.getSuperClass();
+                    superclass = expressionType.getUnresolvedSuperClass(); // 
GROOVY-11815
                     interfaces = expressionType.getInterfaces();
                 } else if (expressionType != null && 
expressionType.isInterface()) {
                     superclass = OBJECT_TYPE;
diff --git a/src/test/groovy/groovy/transform/stc/TypeInferenceSTCTest.groovy 
b/src/test/groovy/groovy/transform/stc/TypeInferenceSTCTest.groovy
index bb12727f5c..dbf1cf374e 100644
--- a/src/test/groovy/groovy/transform/stc/TypeInferenceSTCTest.groovy
+++ b/src/test/groovy/groovy/transform/stc/TypeInferenceSTCTest.groovy
@@ -127,7 +127,7 @@ class TypeInferenceSTCTest extends 
StaticTypeCheckingTestCase {
         shouldFailWithMessages '''
             Object o
             if (o instanceof String) {
-               o.toUpperCase()
+                o.toUpperCase()
             } else {
                 o.toUpperCase() // ensure that type information is reset
             }
@@ -297,6 +297,25 @@ class TypeInferenceSTCTest extends 
StaticTypeCheckingTestCase {
         '''
     }
 
+    // GROOVY-11815
+    void testInstanceOf13() {
+        assertScript '''
+            def c = true ? new ArrayDeque() : new Stack()
+            if (c instanceof Deque) {
+                c.addFirst(1)
+            //  ^ (AbstractCollection<Object> & Serializable & ... & Deque)
+            }
+        '''
+        shouldFailWithMessages '''
+            def c = true ? new ArrayDeque<String>() : new Stack<String>()
+            if (c instanceof Serializable) {
+                c.add(1)
+            //  ^ (AbstractCollection<String> & Serializable & ... & Deque)
+            }
+        ''',
+        'Cannot call 
<UnionType:java.util.AbstractCollection','#add(java.lang.String) with arguments 
[int]'
+    }
+
     // GROOVY-5226
     void testNestedInstanceOf1() {
         assertScript '''