[Core] Add test for #18982

Author: dpiparo

roottest/root/meta/rootcling/CMakeLists.txt

@@ -32,4 +32,9 @@ ROOTTEST_ADD_TEST(ROOT10798
 ROOTTEST_GENERATE_DICTIONARY(streamerInfoStdFunctionDict streamerInfoStdFunction.h LINKDEF streamerInfoStdFunction.xml)
 ROOTTEST_ADD_TEST(streamerInfoStdFunction
                   MACRO streamerInfoStdFunction.C
-                  DEPENDS ${GENERATE_DICTIONARY_TEST})
+                  DEPENDS ${GENERATE_DICTIONARY_TEST})
+
+# Issue #18982
+ROOTTEST_ADD_TEST(selectTemplateInvalidArg
+                  COMMAND ${ROOT_rootcling_CMD} -f selectTemplateInvalidArg.Dict.cc ${CMAKE_CURRENT_SOURCE_DIR}/selectTemplateInvalidArg.h ${CMAKE_CURRENT_SOURCE_DIR}/selectTemplateInvalidArg.LinkDef.h
+                  ERRREF selectTemplateInvalidArg.ref)

roottest/root/meta/rootcling/selectTemplateInvalidArg.LinkDef.h

@@ -0,0 +1,9 @@
+#ifdef __CLING__
+
+#pragma link off all globals;
+#pragma link off all classes;
+#pragma link off all functions;
+
+#pragma link C++ class RtObj2<TNamed>+;
+
+#endif

roottest/root/meta/rootcling/selectTemplateInvalidArg.h

@@ -0,0 +1,14 @@
+#include <TObject.h>
+
+template <class T>
+class RtObj2 : public T
+ {
+  public:
+    RtObj2() {}
+    RtObj2( const T & val ) : T(val) {}
+    ClassDefT(RtObj2,1)
+ } ;
+
+ClassDefT2(RtObj2,T)
+
+ClassImpT(RtObj2,T)

roottest/root/meta/rootcling/selectTemplateInvalidArg.ref

@@ -0,0 +1 @@
+Warning: Unused class rule: RtObj2<TNamed>