bug with incorrect merge of data flow info (KT-104) fixed

idea/src/org/jetbrains/jet/lang/types/DataFlowInfo.java

@@ -163,7 +163,7 @@ public class DataFlowInfo {
             builder.put(variableDescriptor, thisFlags.or(otherFlags));
         }
 
-        ListMultimap<VariableDescriptor, JetType> newTypeInfo = copyTypeInfo();
+        ListMultimap<VariableDescriptor, JetType> newTypeInfo = Multimaps.newListMultimap(Maps.<VariableDescriptor, Collection<JetType>>newHashMap(), ARRAY_LIST_SUPPLIER);
 
         Set<VariableDescriptor> keys = newTypeInfo.keySet();
         keys.retainAll(other.typeInfo.keySet());

idea/testData/checker/infos/Autocasts.jet

@@ -216,3 +216,19 @@ fun returnFunctionLiteral(a: Any?): Function0<Int> =
 fun illegalTupleReturnType(a: Any): (Any, String) = (a, <error>a</error>)
 
 fun declarationInsidePattern(x: (Any, Any)): String = when(x) { is (val a is String, *) => <info descr="Automatically cast to String">a</info>; else => "something" }
+
+fun mergeAutocasts(a: Any?) {
+  if (a is String || a is Int) {
+    a.<error>compareTo</error>("")
+    a.toString()
+  }
+  if (a is Int || a is String) {
+    a.<error>compareTo</error>("")
+  }
+  when (a) {
+    is String, is Any => a.<error>compareTo</error>("")
+  }
+  if (a is String && a is Any) {
+    val i: Int = <info descr="Automatically cast to String">a</info>.length
+  }
+}