diff --git a/java/java-impl/src/com/intellij/psi/impl/PsiElementFactoryImpl.java b/java/java-impl/src/com/intellij/psi/impl/PsiElementFactoryImpl.java
index cbdaa33b5f3f..4a4c8a7620ba 100644
--- a/java/java-impl/src/com/intellij/psi/impl/PsiElementFactoryImpl.java
+++ b/java/java-impl/src/com/intellij/psi/impl/PsiElementFactoryImpl.java
@@ -242,8 +242,11 @@ public class PsiElementFactoryImpl extends PsiJavaParserFacadeImpl implements Ps
       throw new IncorrectOperationException("Cannot create field with type \"<null_type>\".");
     }
     final FileElement treeHolder = DummyHolderFactory.createHolder(myManager, null).getTreeElement();
-    final CompositeElement treeElement =
-    getJavaParsingContext(treeHolder).getDeclarationParsing().parseParameterText(type.getCanonicalText() + " " + name);
+    final String text = type.getCanonicalText() + " " + name;
+    final CompositeElement treeElement = getJavaParsingContext(treeHolder).getDeclarationParsing().parseParameterText(text);
+    if (treeElement == null) {
+      throw new AssertionError("Null element for text = " + text);
+    }
     treeHolder.rawAddChildren(treeElement);
 
     CodeStyleManager codeStyleManager = CodeStyleManager.getInstance(myManager.getProject());
diff --git a/platform/lang-api/src/com/intellij/psi/search/PsiSearchRequest.java b/platform/lang-api/src/com/intellij/psi/search/PsiSearchRequest.java
index 16ccdef9514f..4a0d56fe312b 100644
--- a/platform/lang-api/src/com/intellij/psi/search/PsiSearchRequest.java
+++ b/platform/lang-api/src/com/intellij/psi/search/PsiSearchRequest.java
@@ -18,6 +18,9 @@ public class PsiSearchRequest {
                        boolean caseSensitive,
                        @NotNull RequestResultProcessor processor) {
 
+    if (word.length() == 0) {
+      throw new IllegalArgumentException("Cannot search for elements with empty text");
+    }
     this.searchScope = searchScope;
     this.word = word;
     this.searchContext = searchContext;
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/dsl/GroovyDslExecutor.groovy b/plugins/groovy/src/org/jetbrains/plugins/groovy/dsl/GroovyDslExecutor.groovy
index 4dfb2112225a..44d7dad25b24 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/dsl/GroovyDslExecutor.groovy
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/dsl/GroovyDslExecutor.groovy
@@ -8,9 +8,8 @@ import org.jetbrains.plugins.groovy.dsl.psi.PsiEnhancerCategory
 import org.jetbrains.plugins.groovy.dsl.toplevel.CompositeContextFilter
 import org.jetbrains.plugins.groovy.dsl.toplevel.ContextFilter
 import org.jetbrains.plugins.groovy.dsl.toplevel.GdslMetaClassProperties
-import com.intellij.openapi.project.Project
 
-/**
+ /**
  * @author ilyas
  */
 
@@ -20,6 +19,7 @@ public class GroovyDslExecutor {
 
   private final String myFileName;
   static final String ideaVersion
+  private boolean locked = false
 
   static {
     def major = ApplicationInfo.instance.majorVersion
@@ -52,9 +52,12 @@ public class GroovyDslExecutor {
     mc.initialize()
     script.metaClass = mc
     script.run()
+
+    locked = true
   }
 
   def addClassEnhancer(List<ContextFilter> cts, Closure toDo) {
+    assert !locked : 'Contributing to GDSL is only allowed at the top-level of the *.gdsl script'
     enhancers << Pair.create(CompositeContextFilter.compose(cts, false), toDo)
   }
 
diff --git a/xml/dom-impl/src/com/intellij/xml/impl/dom/AbstractDomChildrenDescriptor.java b/xml/dom-impl/src/com/intellij/xml/impl/dom/AbstractDomChildrenDescriptor.java
index 95a2c47d9cbf..b8baa40361a2 100644
--- a/xml/dom-impl/src/com/intellij/xml/impl/dom/AbstractDomChildrenDescriptor.java
+++ b/xml/dom-impl/src/com/intellij/xml/impl/dom/AbstractDomChildrenDescriptor.java
@@ -115,6 +115,9 @@ public abstract class AbstractDomChildrenDescriptor implements XmlElementDescrip
         @Nullable
         public PsiElement getDeclaration() {
           final PomTarget target = ((CustomDomChildrenDescription)description).getTagNameDescriptor().findDeclaration(finalDomElement);
+          if (target == description) {
+            return childTag;
+          }
           return target == null ? null : PomService.convertToPsi(childTag.getProject(), target);
         }
 
diff --git a/xml/dom-openapi/src/com/intellij/util/xml/converters/values/BooleanValueConverter.java b/xml/dom-openapi/src/com/intellij/util/xml/converters/values/BooleanValueConverter.java
index cc5293155163..a7fa99b038e6 100644
--- a/xml/dom-openapi/src/com/intellij/util/xml/converters/values/BooleanValueConverter.java
+++ b/xml/dom-openapi/src/com/intellij/util/xml/converters/values/BooleanValueConverter.java
@@ -38,6 +38,10 @@ public class BooleanValueConverter extends ResolvingConverter<String> {
      return new BooleanValueConverter(allowEmpty);
   }
 
+  public BooleanValueConverter() {
+    this(false);
+  }
+
   public BooleanValueConverter(final boolean allowEmpty) {
     myAllowEmpty = allowEmpty;
   }