From d2e1b438c6e49397f8cf1ca1f4e6463a89be0210 Mon Sep 17 00:00:00 2001
From: Aleksey Pivovarov <AMPivovarov@gmail.com>
Date: Wed, 7 Dec 2016 17:44:26 +0300
Subject: [PATCH] diff: do not rely on Change.hashCode implementation

follow-up: ea6a028
---
 .../openapi/vcs/changes/CacheChangeProcessor.java      |  2 +-
 .../actions/diff/ChangeDiffRequestProducer.java        | 10 +++++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/CacheChangeProcessor.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/CacheChangeProcessor.java
index c85d48bd8f16..f23f72a3c633 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/CacheChangeProcessor.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/CacheChangeProcessor.java
@@ -241,7 +241,7 @@ public abstract class CacheChangeProcessor extends CacheDiffRequestProcessor<Cac
 
     @Override
     public int hashCode() {
-      return change.hashCode();
+      return ChangeDiffRequestProducer.hashCode(change);
     }
 
     @Override
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/actions/diff/ChangeDiffRequestProducer.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/actions/diff/ChangeDiffRequestProducer.java
index 3e12b05ca98d..13a4d0709303 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/actions/diff/ChangeDiffRequestProducer.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/actions/diff/ChangeDiffRequestProducer.java
@@ -92,7 +92,7 @@ public class ChangeDiffRequestProducer implements DiffRequestProducer {
   public static boolean isEquals(@NotNull Change change1, @NotNull Change change2) {
     if (!Comparing.equal(ChangesUtil.getBeforePath(change1), ChangesUtil.getBeforePath(change2)) ||
         !Comparing.equal(ChangesUtil.getAfterPath(change1), ChangesUtil.getAfterPath(change2))) {
-      // we use Change.hashCode(), so removing this check might violate comparison contract
+      // we use file paths for hashCode, so removing this check might violate comparison contract
       return false;
     }
 
@@ -123,6 +123,14 @@ public class ChangeDiffRequestProducer implements DiffRequestProducer {
     return false;
   }
 
+  public static int hashCode(@NotNull Change change) {
+    return hashCode(change.getBeforeRevision()) + 31 * hashCode(change.getAfterRevision());
+  }
+
+  private static int hashCode(@Nullable ContentRevision revision) {
+    return revision != null ? revision.getFile().hashCode() : 0;
+  }
+
   @Nullable
   public static ChangeDiffRequestProducer create(@Nullable Project project, @NotNull Change change) {
     return create(project, change, Collections.<Key, Object>emptyMap());