GROOVY-10323

Author: eric-milles

base-test/org.eclipse.jdt.groovy.core.tests.compiler/src/org/eclipse/jdt/groovy/core/tests/xform/TypeCheckedTests.java

@@ -4230,6 +4230,31 @@ public void testTypeChecked10320() {
         runConformTest(sources, "3.3");
     }
 
+    @Test
+    public void testTypeChecked10323() {
+        //@formatter:off
+        String[] sources = {
+            "Main.groovy",
+            "class C<T> {\n" +
+            "}\n" +
+            "def <T,T> T m(C<T> c) {\n" +
+            "}\n" +
+            "@groovy.transform.TypeChecked\n" +
+            "void test() {\n" +
+            "  Number n = m(new C<>())\n" +
+            "}\n",
+        };
+        //@formatter:on
+
+        runNegativeTest(sources,
+            "----------\n" +
+            "1. ERROR in Main.groovy (at line 3)\n" +
+            "\tdef <T,T> T m(C<T> c) {\n" +
+            "\t       ^^\n" +
+            "Duplicate type parameter T\n" +
+            "----------\n");
+    }
+
     @Test
     public void testTypeChecked10325() {
         //@formatter:off

base/org.codehaus.groovy25/src/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java

@@ -6339,7 +6339,7 @@ private Map<GenericsTypeName, GenericsType> extractGenericsConnectionsFromArgume
 
             // in case of "<T, U extends Type<T>>" we can learn about "T" from resolved "U"
             Map<GenericsTypeName, GenericsType> connections = Arrays.stream(methodGenericTypes)
-                    .collect(toMap(gt -> new GenericsTypeName(gt.getName()), Function.identity()));
+                    .collect(toMap(gt -> new GenericsTypeName(gt.getName()), gt -> gt, (v,x) -> v));
             extractGenericsConnectionsForSuperClassAndInterfaces(connections, resolvedPlaceholders);
         }
 

base/org.codehaus.groovy30/src/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java

@@ -6009,7 +6009,7 @@ private Map<GenericsTypeName, GenericsType> extractGenericsConnectionsFromArgume
 
             // in case of "<T, U extends Type<T>>" we can learn about "T" from resolved "U"
             Map<GenericsTypeName, GenericsType> connections = Arrays.stream(methodGenericTypes)
-                    .collect(toMap(gt -> new GenericsTypeName(gt.getName()), Function.identity()));
+                    .collect(toMap(gt -> new GenericsTypeName(gt.getName()), gt -> gt, (v,x) -> v));
             extractGenericsConnectionsForSuperClassAndInterfaces(connections, resolvedPlaceholders);
         }
 

base/org.codehaus.groovy40/src/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java

@@ -5491,7 +5491,7 @@ private Map<GenericsTypeName, GenericsType> extractGenericsConnectionsFromArgume
 
             // in case of "<T, U extends Type<T>>" we can learn about "T" from resolved "U"
             Map<GenericsTypeName, GenericsType> connections = Arrays.stream(methodGenericTypes)
-                    .collect(toMap(gt -> new GenericsTypeName(gt.getName()), Function.identity()));
+                    .collect(toMap(gt -> new GenericsTypeName(gt.getName()), gt -> gt, (v,x) -> v));
             extractGenericsConnectionsForSuperClassAndInterfaces(connections, resolvedPlaceholders);
         }