diff --git a/platform/vcs-api/src/com/intellij/openapi/vcs/AbstractVcsHelper.java b/platform/vcs-api/src/com/intellij/openapi/vcs/AbstractVcsHelper.java
index b90eee515c20..68500e0a36a5 100644
--- a/platform/vcs-api/src/com/intellij/openapi/vcs/AbstractVcsHelper.java
+++ b/platform/vcs-api/src/com/intellij/openapi/vcs/AbstractVcsHelper.java
@@ -36,15 +36,20 @@ import org.jetbrains.annotations.Nullable;
 
 import java.awt.*;
 import java.io.File;
-import java.util.Arrays;
-import java.util.Collection;
+import java.util.*;
 import java.util.List;
-import java.util.Map;
 
 /**
  * Component which provides means to invoke different VCS-related services.
  */
 public abstract class AbstractVcsHelper {
+
+  protected final Project myProject;
+
+  protected AbstractVcsHelper(@NotNull Project project) {
+    myProject = project;
+  }
+
   public static AbstractVcsHelper getInstance(Project project) {
     return PeriodicalTasksCloser.getInstance().safeGetService(project, AbstractVcsHelper.class);
   }
@@ -115,14 +120,28 @@ public abstract class AbstractVcsHelper {
    * {@link #showMergeDialog(java.util.List, com.intellij.openapi.vcs.merge.MergeProvider)} without description.
    */
   @NotNull
-  public abstract List<VirtualFile> showMergeDialog(List<VirtualFile> files, MergeProvider provider);
+  public final List<VirtualFile> showMergeDialog(List<VirtualFile> files, MergeProvider provider) {
+    return showMergeDialog(files, provider, new MergeDialogCustomizer());
+  }
 
   /**
    * {@link #showMergeDialog(java.util.List, com.intellij.openapi.vcs.merge.MergeProvider)} without description and with default merge provider
    * for the current VCS.
    */
   @NotNull
-  public abstract List<VirtualFile> showMergeDialog(List<VirtualFile> files);
+  public final List<VirtualFile> showMergeDialog(List<VirtualFile> files) {
+    if (files.isEmpty()) return Collections.emptyList();
+    MergeProvider provider = null;
+    for (VirtualFile virtualFile : files) {
+      final AbstractVcs vcs = ProjectLevelVcsManager.getInstance(myProject).getVcsFor(virtualFile);
+      if (vcs != null) {
+        provider = vcs.getMergeProvider();
+        if (provider != null) break;
+      }
+    }
+    if (provider == null) return Collections.emptyList();
+    return showMergeDialog(files, provider);
+  }
 
   public abstract void showFileHistory(VcsHistoryProvider vcsHistoryProvider, FilePath path, final AbstractVcs vcs,
                                        final String repositoryPath);
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/AbstractVcsHelperImpl.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/AbstractVcsHelperImpl.java
index 702070d17745..be10b7faa5fd 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/AbstractVcsHelperImpl.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/AbstractVcsHelperImpl.java
@@ -88,11 +88,10 @@ import java.util.List;
 public class AbstractVcsHelperImpl extends AbstractVcsHelper {
   private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.vcs.impl.AbstractVcsHelperImpl");
 
-  private final Project myProject;
   private Consumer<VcsException> myCustomHandler = null;
 
-  public AbstractVcsHelperImpl(Project project) {
-    myProject = project;
+  protected AbstractVcsHelperImpl(@NotNull Project project) {
+    super(project);
   }
 
   public void openMessagesView(final VcsErrorViewPanel errorTreeView, final String tabDisplayName) {
@@ -567,12 +566,6 @@ public class AbstractVcsHelperImpl extends AbstractVcsHelper {
     }
   }
 
-  @Override
-  @NotNull
-  public List<VirtualFile> showMergeDialog(List<VirtualFile> files, MergeProvider provider) {
-    return showMergeDialog(files, provider, new MergeDialogCustomizer());
-  }
-
   @Override
   @NotNull
   public List<VirtualFile> showMergeDialog(List<VirtualFile> files, MergeProvider provider, @NotNull MergeDialogCustomizer mergeDialogCustomizer) {
@@ -582,21 +575,6 @@ public class AbstractVcsHelperImpl extends AbstractVcsHelper {
     return fileMergeDialog.getProcessedFiles();
   }
 
-  @NotNull
-  public List<VirtualFile> showMergeDialog(final List<VirtualFile> files) {
-    if (files.isEmpty()) return Collections.emptyList();
-    MergeProvider provider = null;
-    for (VirtualFile virtualFile : files) {
-      final AbstractVcs vcs = ProjectLevelVcsManager.getInstance(myProject).getVcsFor(virtualFile);
-      if (vcs != null) {
-        provider = vcs.getMergeProvider();
-        if (provider != null) break;
-      }
-    }
-    if (provider == null) return Collections.emptyList();
-    return showMergeDialog(files, provider);
-  }
-
   private static DiffContent getContentForVersion(final VcsFileRevision version, final File file) throws IOException, VcsException {
     VirtualFile vFile = LocalFileSystem.getInstance().findFileByIoFile(file);
     if (vFile != null && (version instanceof CurrentRevision) && !vFile.getFileType().isBinary()) {
diff --git a/plugins/hg4idea/testSrc/org/zmlx/hg4idea/test/HgMockVcsHelper.java b/plugins/hg4idea/testSrc/org/zmlx/hg4idea/test/HgMockVcsHelper.java
index c8ffe9e6b71d..301fd8be594b 100644
--- a/plugins/hg4idea/testSrc/org/zmlx/hg4idea/test/HgMockVcsHelper.java
+++ b/plugins/hg4idea/testSrc/org/zmlx/hg4idea/test/HgMockVcsHelper.java
@@ -16,6 +16,7 @@
 package org.zmlx.hg4idea.test;
 
 import com.intellij.ide.errorTreeView.HotfixData;
+import com.intellij.openapi.project.Project;
 import com.intellij.openapi.vcs.*;
 import com.intellij.openapi.vcs.annotate.AnnotationProvider;
 import com.intellij.openapi.vcs.annotate.FileAnnotation;
@@ -50,6 +51,10 @@ public class HgMockVcsHelper extends AbstractVcsHelper {
 
   private Collection<VcsHelperListener> myListeners = new THashSet<VcsHelperListener>();
 
+  public HgMockVcsHelper(@NotNull Project project) {
+    super(project);
+  }
+
   @Override
   public void showErrors(List<VcsException> abstractVcsExceptions, @NotNull String tabDisplayName) {
   }
@@ -118,18 +123,6 @@ public class HgMockVcsHelper extends AbstractVcsHelper {
     return null;
   }
 
-  @NotNull
-  @Override
-  public List<VirtualFile> showMergeDialog(List<VirtualFile> files, MergeProvider provider) {
-    return null;
-  }
-
-  @NotNull
-  @Override
-  public List<VirtualFile> showMergeDialog(List<VirtualFile> files) {
-    return null;
-  }
-
   @Override
   public void showFileHistory(VcsHistoryProvider vcsHistoryProvider, FilePath path, AbstractVcs vcs, String repositoryPath) {
   }