From da864aeccd0f19c4494eabbca8610cf26075a2a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Fournier?= <clement.fournier@tu-dresden.de>
Date: Sat, 24 Aug 2024 16:48:03 +0200
Subject: [PATCH 1/2] Fix #5167 - issue with type projection

---
 .../pmd/lang/java/types/TypeOps.java          |  7 ++++
 .../pmd/lang/java/types/TypeOpsTest.kt        | 37 +++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/types/TypeOps.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/types/TypeOps.java
index 051ea91c027..a6ac8828196 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/types/TypeOps.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/types/TypeOps.java
@@ -1170,6 +1170,13 @@ public JTypeMirror visitClass(JClassType t, RecursionStop recursionStop) {
                     } else if (!upwards) {
                         // If Ai is a type that mentions a restricted type variable, then Ai' is undefined.
                         return NO_DOWN_PROJECTION;
+                    } else if (u instanceof JWildcardType) {
+                        // The rest of this function, below, treats u as the bound of a wildcard,
+                        // but if u is already a wildcard (and therefore ai was a wildcard), we
+                        // are already done.
+                        newTargs.add(u);
+                        change = true;
+                        continue;
                     }
 
                     change = true;
diff --git a/pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/types/TypeOpsTest.kt b/pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/types/TypeOpsTest.kt
index 55a1b19a82b..421a778c4a0 100644
--- a/pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/types/TypeOpsTest.kt
+++ b/pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/types/TypeOpsTest.kt
@@ -95,7 +95,44 @@ class TypeOpsTest : FunSpec({
 
 
             }
+            test("#5167 problem in projection") {
+                val (acu, spy) = javaParser.parseWithTypeInferenceSpy(
+                    """
+import java.lang.annotation.Annotation;
+interface Bar<T> {
+    Baz<T> getBaz();
+}
+
+interface Predicate<T> {
+    boolean check(T t);
+}
+interface Stream<T>{
+    T findSome();
+}
+interface Baz<T>{
+    Stream<Bar<? super T>> filterMethods(Predicate<? super T> p);
+}
+
+class Foo {
+
+    private static Bar<?> foo(
+        Bar<?> type, Class<? extends Annotation> annotation, boolean required) {
+        var method = type.getBaz().filterMethods(m -> true).findSome();
+        return method;
+    }
+}
+            """.trimIndent()
+                )
+
+                val (barT) = acu.declaredTypeSignatures()
+                val methodId = acu.varId("method")
+
+                spy.shouldBeOk {
+                    methodId shouldHaveType barT[`?`]
+                }
+            }
         }
     }
 
+
 })

From be47aab26543d40c31a9713df4baf60abf0bb1db Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Mart=C3=ADn=20Sotuyo=20Dodero?=
 <juan.sotuyo@pedidosya.com>
Date: Sat, 24 Aug 2024 18:18:38 -0300
Subject: [PATCH 2/2] Update changelog, refs #5167

---
 docs/pages/release_notes.md | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/docs/pages/release_notes.md b/docs/pages/release_notes.md
index c12e6be8405..1bc6f6fc002 100644
--- a/docs/pages/release_notes.md
+++ b/docs/pages/release_notes.md
@@ -17,7 +17,9 @@ This is a {{ site.pmd.release_type }} release.
 ### 🐛 Fixed Issues
 * apex-performance
   * [#5139](https://github.com/pmd/pmd/issues/5139): \[apex] OperationWithHighCostInLoop not firing in triggers
-* pmd-bestpractices
+* java
+  * [#5167](https://github.com/pmd/pmd/pull/5167): \[java] java.lang.IllegalArgumentException: \<\?\> cannot be a wildcard bound
+* java-bestpractices
   * [#5145](https://github.com/pmd/pmd/issues/5145): \[java] False positive UnusedPrivateMethod
 * plsql-bestpractices
   * [#5132](https://github.com/pmd/pmd/issues/5132): \[plsql] TomKytesDespair - exception for more complex exception handler