do not mark FSRecords as dirty upon opening or successful find of

existing root

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

@@ -283,7 +283,9 @@ public class FSRecords {
         myRecords = new ResizeableMappedFile(recordsFile, 20 * 1024, storageLockContext,
                                              PagedFileStorage.BUFFER_SIZE, aligned, IOUtil.ourByteBuffersUseNativeByteOrder);
 
-        if (myRecords.length() == 0) {
+        boolean initial = myRecords.length() == 0;
+
+        if (initial) {
           cleanRecord(0); // Clean header
           cleanRecord(1); // Create root record
           setCurrentVersion();
@@ -296,7 +298,7 @@ public class FSRecords {
         if (myRecords.getInt(HEADER_CONNECTION_STATUS_OFFSET) != SAFELY_CLOSED_MAGIC) {
           throw new IOException("FS repository wasn't safely shut down");
         }
-        markDirty();
+        if (initial) markDirty();
         scanFreeRecords();
       }
       catch (Exception e) { // IOException, IllegalArgumentException
@@ -809,7 +811,6 @@ public class FSRecords {
     w.lock();
 
     try {
-      DbConnection.markDirty();
       if (ourStoreRootsSeparately) {
         try {
           try (LineNumberReader stream = new LineNumberReader(new BufferedReader(new InputStreamReader(new FileInputStream(DbConnection.myRootsFile))))) {
@@ -823,6 +824,8 @@ public class FSRecords {
             }
           }
         } catch (FileNotFoundException ignored) {}
+
+        DbConnection.markDirty();
         try (Writer stream = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(DbConnection.myRootsFile, true)))) {
           int id = createRecord();
           stream.write(id + " " + rootUrl + "\n");
@@ -830,7 +833,7 @@ public class FSRecords {
         }
       }
 
-      final int root = getNames().enumerate(rootUrl);
+      int root = getNames().tryEnumerate(rootUrl);
 
       final DataInputStream input = readAttribute(ROOT_RECORD_ID, ourChildrenAttr);
       int[] names = ArrayUtil.EMPTY_INT_ARRAY;
@@ -860,6 +863,9 @@ public class FSRecords {
         }
       }
 
+      DbConnection.markDirty();
+      root = getNames().enumerate(rootUrl);
+
       int id;
       try (DataOutputStream output = writeAttribute(ROOT_RECORD_ID, ourChildrenAttr)) {
         id = createRecord();