[ann] Exceptions with interfaces in multi-catch: correct erasure

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting7/MultiCatch.java

@@ -56,6 +56,13 @@ abstract class C {
     try { f(); } catch (E1 | E2 e) { <error descr="Incompatible types. Found: 'C.E1 | C.E2', required: 'C.E2'">E2 ee = e;</error> }
     try { f(); } catch (E1 | E2 e) { <error descr="Cannot assign a value to final variable 'e'">e = new E1()</error>; }
     try { f(); } catch (E1 | E2 e) { <error descr="Incompatible types. Found: 'C.E', required: 'C.E1 | C.E2'">e = new E()</error>; }
+
+    try { g(); }
+    catch (IE1 | IE2 e) {
+      Class<? extends E> clazz1 = e.getClass();
+      <error descr="Incompatible types. Found: 'java.lang.Class<? extends C.E>', required: 'java.lang.Class<? extends C.IE1>'">Class<? extends IE1> clazz2 = e.getClass();</error>
+      <error descr="Incompatible types. Found: 'java.lang.Class<? extends C.E>', required: 'java.lang.Class<? extends C.I>'">Class<? extends I> clazz3 = e.getClass();</error>
+    }
   }
 }
 

java/openapi/src/com/intellij/psi/util/PsiTypesUtil.java

@@ -116,4 +116,23 @@ public class PsiTypesUtil {
   public static PsiClassType getClassType(@NotNull PsiClass psiClass) {
     return JavaPsiFacade.getElementFactory(psiClass.getProject()).createType(psiClass);
   }
+
+  @Nullable
+  public static PsiClassType getLowestUpperBoundClassType(@NotNull final PsiDisjunctionType type) {
+    final PsiType lub = type.getLeastUpperBound();
+    if (lub instanceof PsiClassType) {
+      return (PsiClassType)lub;
+    }
+    else if (lub instanceof PsiIntersectionType) {
+      for (PsiType subType : ((PsiIntersectionType)lub).getConjuncts()) {
+        if (subType instanceof PsiClassType) {
+          final PsiClass aClass = ((PsiClassType)subType).resolve();
+          if (aClass != null && !aClass.isInterface()) {
+            return (PsiClassType)subType;
+          }
+        }
+      }
+    }
+    return null;
+  }
 }

java/openapi/src/com/intellij/psi/util/TypeConversionUtil.java

@@ -23,7 +23,6 @@ import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
 import com.intellij.psi.search.GlobalSearchScope;
 import com.intellij.psi.tree.IElementType;
-import com.intellij.util.Function;
 import com.intellij.util.Processor;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.HashMap;
@@ -33,7 +32,10 @@ import gnu.trove.TObjectIntHashMap;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import java.util.*;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
 
 public class TypeConversionUtil {
   private static final Logger LOG = Logger.getInstance("#com.intellij.psi.util.TypeConversionUtil");
@@ -1189,10 +1191,8 @@ public class TypeConversionUtil {
 
       @Override
       public PsiType visitDisjunctionType(PsiDisjunctionType disjunctionType) {
-        final List<PsiType> erased = ContainerUtil.map(disjunctionType.getDisjunctions(), new Function<PsiType, PsiType>() {
-          @Override public PsiType fun(PsiType psiType) { return erasure(psiType, beforeSubstitutor); }
-        });
-        return disjunctionType.newDisjunctionType(erased);
+        final PsiClassType lub = PsiTypesUtil.getLowestUpperBoundClassType(disjunctionType);
+        return lub != null ? erasure(lub, beforeSubstitutor) : disjunctionType;
       }
     });
   }