From 98bf054a7a0a91dad42b1de3083caceac261f35a Mon Sep 17 00:00:00 2001
From: Eugene Zhuravlev <jeka@intellij.com>
Date: Mon, 17 Sep 2018 13:38:06 +0200
Subject: [PATCH] fileNameChangedEvent: do not notify BuildManager if file name
 has not actually changed; ensure deleted-changed notification sequence
 (relevant for case-insensitive file systems)

---
 .../impl/TranslatingCompilerFilesMonitor.java       | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java b/java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java
index 15509e2469c5..7e117cbe8b12 100644
--- a/java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java
+++ b/java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java
@@ -149,8 +149,12 @@ public class TranslatingCompilerFilesMonitor implements BulkFileListener {
 
     checkIntersection(filesChanged, filesDeleted);
 
-    notifyFilesChanged(filesChanged);
+    // If a file name differs ony in case, on case-insensitive file systems such name denotes still the same file.
+    // In this situation filesDeleted and filesChanged sets will contain paths differing only in case.
+    // Thus the order in which BuildManager is notified, is important:
+    // first deleted paths notification and only then changed paths notification
     notifyFilesDeleted(filesDeleted);
+    notifyFilesChanged(filesChanged);
   }
 
   // todo: temporary check to verify events correctess
@@ -194,11 +198,16 @@ public class TranslatingCompilerFilesMonitor implements BulkFileListener {
                                        @NotNull Collection<? super File> filesDeleted,
                                        @NotNull Collection<? super File> filesChanged) {
     if (VirtualFile.PROP_NAME.equals(event.getPropertyName())) {
+      final String oldName = (String)event.getOldValue();
+      final String newName = (String)event.getNewValue();
+      if (Comparing.equal(oldName, newName)) {
+        // Old and new names may actually be the same: sometimes such events are sent by VFS
+        return;
+      }
       final VirtualFile eventFile = event.getFile();
       if (isInContentOfOpenedProject(eventFile)) {
         final VirtualFile parent = eventFile.getParent();
         if (parent != null) {
-          final String oldName = (String)event.getOldValue();
           final String root = parent.getPath() + "/" + oldName;
           if (eventFile.isDirectory()) {
             VfsUtilCore.visitChildrenRecursively(eventFile, new VirtualFileVisitor() {