file and doc mod stamps should be equal after save

platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VirtualFileSystemEntry.java

@@ -69,6 +69,10 @@ public abstract class VirtualFileSystemEntry extends NewVirtualFile {
   private volatile VirtualDirectoryImpl myParent;
   private volatile int myFlags;
   private volatile int myId;
+  
+  static {
+    assert (~ALL_FLAGS_MASK) == LocalTimeCounter.TIME_MASK;
+  }
 
   public VirtualFileSystemEntry(int nameId, VirtualDirectoryImpl parent, int id, @PersistentFS.Attributes int attributes) {
     myParent = parent;

platform/util/src/com/intellij/util/LocalTimeCounter.java

@@ -18,12 +18,14 @@ package com.intellij.util;
 import java.util.concurrent.atomic.AtomicLong;
 
 public class LocalTimeCounter {
+  /**
+   * VirtualFile.modificationStamp is kept modulo this mask, and is compared with other stamps. Let's avoid accidental stamp inequalities 
+   * by normalizing all of them. 
+   */
+  public static final int TIME_MASK = 0x00ffffff;
   private static final AtomicLong ourCurrentTime = new AtomicLong();
 
-  private LocalTimeCounter() {
-  }
-
   public static long currentTime() {
-    return ourCurrentTime.incrementAndGet();
+    return TIME_MASK & (int)ourCurrentTime.incrementAndGet();
   }
 }