diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/BasicDefaultVcsRootPolicy.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/BasicDefaultVcsRootPolicy.java
index 0008113db02e..cbc508087506 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/BasicDefaultVcsRootPolicy.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/BasicDefaultVcsRootPolicy.java
@@ -50,7 +50,7 @@ public class BasicDefaultVcsRootPolicy extends DefaultVcsRootPolicy {
     return result;
   }
 
-  public boolean matchesDefaultMapping(final VirtualFile file, final Object matchContext) {
+  public boolean matchesDefaultMapping(@NotNull final VirtualFile file, final Object matchContext) {
     return VfsUtil.isAncestor(ProjectBaseDirectory.getInstance(myProject).getBaseDir(myBaseDir), file, false);
   }
 
@@ -60,7 +60,7 @@ public class BasicDefaultVcsRootPolicy extends DefaultVcsRootPolicy {
   }
 
   @Nullable
-  public VirtualFile getVcsRootFor(final VirtualFile file) {
+  public VirtualFile getVcsRootFor(@NotNull final VirtualFile file) {
     return ProjectBaseDirectory.getInstance(myProject).getBaseDir(myBaseDir);
   }
 
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/DefaultVcsRootPolicy.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/DefaultVcsRootPolicy.java
index 57eee5984492..62b354648c67 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/DefaultVcsRootPolicy.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/DefaultVcsRootPolicy.java
@@ -38,13 +38,13 @@ public abstract class DefaultVcsRootPolicy {
   @NotNull
   public abstract List<VirtualFile> getDefaultVcsRoots(@NotNull NewMappings mappingList, @NotNull String vcsName);
 
-  public abstract boolean matchesDefaultMapping(final VirtualFile file, final Object matchContext);
+  public abstract boolean matchesDefaultMapping(@NotNull VirtualFile file, final Object matchContext);
 
   @Nullable
   public abstract Object getMatchContext(final VirtualFile file);
 
   @Nullable
-  public abstract VirtualFile getVcsRootFor(final VirtualFile file);
+  public abstract VirtualFile getVcsRootFor(@NotNull VirtualFile file);
 
   @NotNull
   public abstract Collection<VirtualFile> getDirtyRoots();
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/ModuleDefaultVcsRootPolicy.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/ModuleDefaultVcsRootPolicy.java
index 1c2ffffe52dd..b00fc6958a2c 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/ModuleDefaultVcsRootPolicy.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/ModuleDefaultVcsRootPolicy.java
@@ -98,7 +98,7 @@ public class ModuleDefaultVcsRootPolicy extends DefaultVcsRootPolicy {
   }
 
   @Override
-  public boolean matchesDefaultMapping(final VirtualFile file, final Object matchContext) {
+  public boolean matchesDefaultMapping(@NotNull final VirtualFile file, final Object matchContext) {
     if (matchContext != null) {
       return true;
     }
@@ -113,17 +113,17 @@ public class ModuleDefaultVcsRootPolicy extends DefaultVcsRootPolicy {
 
   @Override
   @Nullable
-  public VirtualFile getVcsRootFor(final VirtualFile file) {
-    if (myBaseDir != null && PeriodicalTasksCloser.getInstance().safeGetService(myProject, FileIndexFacade.class)
-      .isValidAncestor(myBaseDir, file)) {
+  public VirtualFile getVcsRootFor(@NotNull VirtualFile file) {
+    FileIndexFacade indexFacade = PeriodicalTasksCloser.getInstance().safeGetService(myProject, FileIndexFacade.class);
+    if (myBaseDir != null && indexFacade.isValidAncestor(myBaseDir, file)) {
       return myBaseDir;
     }
-    final VirtualFile contentRoot = ProjectRootManager.getInstance(myProject).getFileIndex().getContentRootForFile(file, Registry.is("ide.hide.excluded.files"));
+    VirtualFile contentRoot = ProjectRootManager.getInstance(myProject).getFileIndex().getContentRootForFile(file, Registry.is("ide.hide.excluded.files"));
     if (contentRoot != null && contentRoot.isDirectory()) {
       return contentRoot;
     }
     if (ProjectKt.isDirectoryBased(myProject)) {
-      final VirtualFile ideaDir = ProjectKt.getStateStore(myProject).getDirectoryStoreFile();
+      VirtualFile ideaDir = ProjectKt.getStateStore(myProject).getDirectoryStoreFile();
       if (ideaDir != null && VfsUtilCore.isAncestor(ideaDir, file, false)) {
         return ideaDir;
       }
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/ProjectLevelVcsManagerImpl.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/ProjectLevelVcsManagerImpl.java
index 660436c6627c..089a98929f99 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/ProjectLevelVcsManagerImpl.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/ProjectLevelVcsManagerImpl.java
@@ -295,6 +295,7 @@ public class ProjectLevelVcsManagerImpl extends ProjectLevelVcsManagerEx impleme
   @Override
   @Nullable
   public VirtualFile getVcsRootFor(@Nullable final VirtualFile file) {
+    if (file == null) return null;
     final VcsDirectoryMapping mapping = myMappings.getMappingFor(file);
     if (mapping == null) {
       return null;
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/projectlevelman/NewMappings.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/projectlevelman/NewMappings.java
index cac610d432c6..024f698daf03 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/projectlevelman/NewMappings.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/impl/projectlevelman/NewMappings.java
@@ -247,7 +247,7 @@ public class NewMappings {
     return mapping.getVcs();
   }
 
-  private boolean fileMatchesMapping(final VirtualFile file,
+  private boolean fileMatchesMapping(@NotNull VirtualFile file,
                                      final Object matchContext,
                                      final String systemIndependentPath,
                                      final VcsDirectoryMapping mapping) {