foreach loop variable shouldn't be visible from the loop expression (IDEA-55859)

java/java-impl/src/com/intellij/codeInsight/daemon/impl/analysis/GenericsHighlightUtil.java

@@ -701,7 +701,7 @@ public class GenericsHighlightUtil {
   public static HighlightInfo checkForeachLoopParameterType(PsiForeachStatement statement) {
     final PsiParameter parameter = statement.getIterationParameter();
     final PsiExpression expression = statement.getIteratedValue();
-    if (expression == null) return null;
+    if (expression == null || expression.getType() == null) return null;
     final PsiType itemType = getCollectionItemType(expression);
     if (itemType == null) {
       String description = JavaErrorMessages.message("foreach.not.applicable",

java/java-impl/src/com/intellij/psi/impl/source/tree/java/PsiForeachStatementImpl.java

@@ -22,9 +22,8 @@ import com.intellij.psi.impl.source.Constants;
 import com.intellij.psi.impl.source.tree.ChildRole;
 import com.intellij.psi.impl.source.tree.CompositePsiElement;
 import com.intellij.psi.scope.PsiScopeProcessor;
-import com.intellij.psi.scope.util.PsiScopesUtil;
-import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.tree.ChildRoleBase;
+import com.intellij.psi.tree.IElementType;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -126,16 +125,11 @@ public class PsiForeachStatementImpl extends CompositePsiElement implements PsiF
 
   public boolean processDeclarations(@NotNull PsiScopeProcessor processor, @NotNull ResolveState state, PsiElement lastParent, @NotNull PsiElement place) {
     processor.handleEvent(PsiScopeProcessor.Event.SET_DECLARATION_HOLDER, this);
-    if (lastParent == null || lastParent.getParent() != this)
+    if (lastParent == null || lastParent.getParent() != this || lastParent == getIteratedValue())
       // Parent element should not see our vars
       return true;
 
-    final PsiParameter iterationParameter = getIterationParameter();
-    if (iterationParameter != null) {
-      return processor.execute(iterationParameter, state);
-    }
-
-    return PsiScopesUtil.walkChildrenScopes(this, processor, state, lastParent, place);
+    return processor.execute(getIterationParameter(), state);
   }
 
   public void accept(@NotNull PsiElementVisitor visitor) {

java/java-tests/testData/codeInsight/completion/smartType/ForeachLoopVariableInIterableExpression.java

@@ -0,0 +1,5 @@
+public class Bar {{
+        for (java.util.List trololo : trolo<caret>) {
+
+        }
+    } }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting/LocalVariableInitialization.java

@@ -181,7 +181,7 @@ public class a  {
     }
 
     void forEachParam(java.io.File x) {
-        for (java.io.File f: <error descr="Variable 'f' might not have been initialized">f</error>.listFiles()) {
+        for (java.io.File f: <error descr="Cannot resolve symbol 'f'">f</error>.listFiles()) {
            forEachParam(f);
         }
     }

java/java-tests/testSrc/com/intellij/codeInsight/completion/SmartTypeCompletionTest.java

@@ -910,6 +910,8 @@ public class SmartTypeCompletionTest extends LightFixtureCompletionTestCase {
 
   public void testEmptyListWithCollectionsPrefix() throws Throwable { doItemTest(); }
 
+  public void testForeachLoopVariableInIterableExpression() throws Throwable { doAntiTest(); }
+
   public void testStaticallyImportedMagicMethod() throws Throwable {
     configureByTestName();
     assertStringItems("foo");