From 092aa296d0f208ceefe8d2b7046a397f11509c0b Mon Sep 17 00:00:00 2001
From: Roman Shevchenko <roman.shevchenko@jetbrains.com>
Date: Mon, 13 Aug 2012 19:45:31 +0400
Subject: [PATCH] Refresh symlinks radically

---
 .../vfs/newvfs/persistent/RefreshWorker.java  | 20 +++++++-
 .../vfs/local/SymlinkHandlingTest.java        | 47 ++++++++++++++-----
 2 files changed, 55 insertions(+), 12 deletions(-)

diff --git a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/RefreshWorker.java b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/RefreshWorker.java
index 1d2454c4238f..6dcefd675e15 100644
--- a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/RefreshWorker.java
+++ b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/RefreshWorker.java
@@ -77,7 +77,9 @@ public class RefreshWorker {
 
       boolean checkFurther = true;
       final VirtualFileSystemEntry parent = file.getParent();
-      if (parent != null && checkAndScheduleAttributesChange(parent, file, attributes)) {
+      if (parent != null &&
+          (checkAndScheduleAttributesChange(parent, file, attributes) ||
+           checkAndScheduleSymLinkTargetChange(parent, file, attributes, fs))) {
         // ignore everything else
         checkFurther = false;
       }
@@ -201,6 +203,22 @@ public class RefreshWorker {
     }
   }
 
+  private boolean checkAndScheduleSymLinkTargetChange(@NotNull VirtualFileSystemEntry parent,
+                                                      @NotNull VirtualFile child,
+                                                      @NotNull FileAttributes childAttributes,
+                                                      @NotNull NewVirtualFileSystem fs) {
+    if (childAttributes.isSymLink()) {
+      final String currentTarget = child.getCanonicalPath();
+      final String upToDateTarget = fs.resolveSymLink(child);
+      if (!Comparing.equal(currentTarget, upToDateTarget)) {
+        scheduleDeletion(child);
+        scheduleReCreation(parent, child.getName(), childAttributes.isDirectory());
+        return true;
+      }
+    }
+    return false;
+  }
+
   private void scheduleWritableAttributeChange(@NotNull VirtualFileSystemEntry file, boolean currentWritable, boolean upToDateWritable) {
     myEvents.add(new VFilePropertyChangeEvent(null, file, VirtualFile.PROP_WRITABLE, currentWritable, upToDateWritable, true));
   }
diff --git a/platform/platform-tests/testSrc/com/intellij/openapi/vfs/local/SymlinkHandlingTest.java b/platform/platform-tests/testSrc/com/intellij/openapi/vfs/local/SymlinkHandlingTest.java
index 956f44fe865d..faf94e941fc8 100644
--- a/platform/platform-tests/testSrc/com/intellij/openapi/vfs/local/SymlinkHandlingTest.java
+++ b/platform/platform-tests/testSrc/com/intellij/openapi/vfs/local/SymlinkHandlingTest.java
@@ -242,26 +242,51 @@ public class SymlinkHandlingTest extends LightPlatformLangTestCase {
                !vFile2.isValid() && vFile1 != null && !vFile1.isDirectory() && vFile1.isSymLink());
   }
 
-  public void testLinkSwitch() throws Exception {
-    final File targetDir1 = createTempDirectory(myTempDir, "targetDir1", "");
-    final File targetDir2 = createTempDirectory(myTempDir, "targetDir2", "");
+  public void testDirLinkSwitch() throws Exception {
+    final File targetDir1 = createTempDirectory(myTempDir, "target1.", ".dir");
+    final File targetDir2 = createTempDirectory(myTempDir, "target2.", ".dir");
     assertTrue(new File(targetDir1, "child1.txt").createNewFile());
     assertTrue(new File(targetDir2, "child11.txt").createNewFile());
     assertTrue(new File(targetDir2, "child12.txt").createNewFile());
 
     final File link = createTempLink(targetDir1.getPath(), myTempDir + "/link");
-    VirtualFile vLink = refreshAndFind(link);
-    assertTrue("link=" + link + ", vLink=" + vLink,
-               vLink != null && vLink.isDirectory() && vLink.isSymLink());
-    assertEquals(1, vLink.getChildren().length);
+    final VirtualFile vLink1 = refreshAndFind(link);
+    assertTrue("link=" + link + ", vLink=" + vLink1,
+               vLink1 != null && vLink1.isDirectory() && vLink1.isSymLink());
+    assertEquals(1, vLink1.getChildren().length);
 
     assertTrue(link.toString(), link.delete());
     createTempLink(targetDir2.getPath(), myTempDir + "/" + link.getName());
 
-    vLink = refreshAndFind(link);
-    assertTrue("link=" + link + ", vLink=" + vLink,
-               vLink != null && vLink.isDirectory() && vLink.isSymLink());
-    assertEquals(2, vLink.getChildren().length);
+    refresh();
+    assertFalse(vLink1.isValid());
+    final VirtualFile vLink2 = myFileSystem.findFileByIoFile(link);
+    assertTrue("link=" + link + ", vLink=" + vLink2,
+               vLink2 != null && vLink2.isDirectory() && vLink2.isSymLink());
+    assertEquals(2, vLink2.getChildren().length);
+  }
+
+  public void testFileLinkSwitch() throws Exception {
+    final File target1 = createTempFile(myTempDir, "target1.", ".txt");
+    FileUtil.writeToFile(target1, "some text");
+    final File target2 = createTempFile(myTempDir, "target2.", ".txt");
+    FileUtil.writeToFile(target2, "some quite another text");
+
+    final File link = createTempLink(target1.getPath(), myTempDir + "/link");
+    final VirtualFile vLink1 = refreshAndFind(link);
+    assertTrue("link=" + link + ", vLink=" + vLink1,
+               vLink1 != null && !vLink1.isDirectory() && vLink1.isSymLink());
+    assertEquals(FileUtil.loadFile(target1), VfsUtilCore.loadText(vLink1));
+
+    assertTrue(link.toString(), link.delete());
+    createTempLink(target2.getPath(), myTempDir + "/" + link.getName());
+
+    refresh();
+    assertFalse(vLink1.isValid());
+    final VirtualFile vLink2 = myFileSystem.findFileByIoFile(link);
+    assertTrue("link=" + link + ", vLink=" + vLink2,
+               vLink2 != null && !vLink2.isDirectory() && vLink2.isSymLink());
+    assertEquals(FileUtil.loadFile(target2), VfsUtilCore.loadText(vLink2));
   }
 
   public void testContentSynchronization() throws Exception {