Fixed type common super type computation when type params are involved (

#2894)

Signed-off-by: Sebastian Zarnekow <sebastian.zarnekow@gmail.com>

org.eclipse.xtend.core.tests/src/org/eclipse/xtend/core/tests/compiler/CompilerBug2351Test.xtend

@@ -0,0 +1,161 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Sebastian Zarnekow (http://www.itemis.eu) and others.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package org.eclipse.xtend.core.tests.compiler
+
+import org.junit.Test
+
+/**
+ * @author Sebastian - Initial contribution and API
+ */
+class CompilerBug2351Test extends AbstractXtendCompilerTest {
+
+	@Test def void test_01() {
+		assertCompilesTo(
+			'''
+			package p
+			
+			import java.math.BigDecimal
+			
+			class C {
+				def Object m(int i) {
+					val r = switch(i) {
+						case 1: 1.0 // double
+						case 2: 1.0bd // BigDecimal
+						default: weird("")
+					}
+					return r	
+				}
+				
+				private def <T> T weird(Object object) {
+					return null;
+				}
+			}
+			''',
+			'''
+			package p;
+			
+			import java.math.BigDecimal;
+			
+			@SuppressWarnings("all")
+			public class C {
+			  public Object m(final int i) {
+			    Object _switchResult = null;
+			    switch (i) {
+			      case 1:
+			        _switchResult = Double.valueOf(1.0);
+			        break;
+			      case 2:
+			        _switchResult = new BigDecimal("1.0");
+			        break;
+			      default:
+			        _switchResult = this.<Object>weird("");
+			        break;
+			    }
+			    final Object r = _switchResult;
+			    return r;
+			  }
+			
+			  private <T extends Object> T weird(final Object object) {
+			    return null;
+			  }
+			}
+			'''
+		)
+	}
+
+	@Test def void test_02() {
+		assertCompilesTo(
+			'''
+			package p
+			
+			import java.math.BigDecimal
+			
+			class C {
+				def void m() {
+						val s1 = switch 45 { // int
+							case 2: 1
+							case 3: 3.0
+							case 78: exit('.')
+							case 4: 4.0 / 5.0
+							default: 6
+						}
+						val s2 = switch 45 {                       // Number
+						        case 78: exit('.')
+						        case 2: 1
+						        case 3: 3.0
+						        case 4: 4.0/5.0
+						        default: 6 
+						} 
+						s1.toString
+						s2.toString
+					}
+				
+					def <T> T exit(String message) {
+						throw new UnsupportedOperationException(message)
+					}
+			}
+			''',
+			'''
+			package p;
+			
+			@SuppressWarnings("all")
+			public class C {
+			  public void m() {
+			    Number _switchResult = null;
+			    final int _switchValue = 45;
+			    switch (_switchValue) {
+			      case 2:
+			        _switchResult = Integer.valueOf(1);
+			        break;
+			      case 3:
+			        _switchResult = Double.valueOf(3.0);
+			        break;
+			      case 78:
+			        _switchResult = ((Number)this.<Number>exit("."));
+			        break;
+			      case 4:
+			        _switchResult = Double.valueOf((4.0 / 5.0));
+			        break;
+			      default:
+			        _switchResult = Integer.valueOf(6);
+			        break;
+			    }
+			    final Number s1 = ((Number)_switchResult);
+			    Number _switchResult_1 = null;
+			    final int _switchValue_1 = 45;
+			    switch (_switchValue_1) {
+			      case 78:
+			        _switchResult_1 = ((Number)this.<Number>exit("."));
+			        break;
+			      case 2:
+			        _switchResult_1 = Integer.valueOf(1);
+			        break;
+			      case 3:
+			        _switchResult_1 = Double.valueOf(3.0);
+			        break;
+			      case 4:
+			        _switchResult_1 = Double.valueOf((4.0 / 5.0));
+			        break;
+			      default:
+			        _switchResult_1 = Integer.valueOf(6);
+			        break;
+			    }
+			    final Number s2 = ((Number)_switchResult_1);
+			    s1.toString();
+			    s2.toString();
+			  }
+			
+			  public <T extends Object> T exit(final String message) {
+			    throw new UnsupportedOperationException(message);
+			  }
+			}
+			'''
+		)
+	}
+}