DiskStoreID.compare treat different DiskStoreID with same leastSig as equal

When reviewing code, I found this actually is a bug, and will impact our 

checkForConflict() to throw CME in following case:

stamps's DiskStoreID is: 5a42b9ec2e6e45db-87559e428bd3ad67

tag's DiskStoreID is: a870e3a0126e4b0d-87559e428bd3ad67

tag is actually bigger than stamp's. But in current code, they will be treated as equal. 

I wrote a junit test to reproduce this problem.

 

The root cause is:

diff --git a/geode-core/src/main/java/org/apache/geode/internal/cache/persistence/DiskStoreID.java b/geode-core/src/main/java/org/apache/geode/internal/cache/persistence/DiskStoreID.java

index 601d24899..0392e92dd 100644

• • • • a/geode-core/src/main/java/org/apache/geode/internal/cache/persistence/DiskStoreID.java*

+++ b/geode-core/src/main/java/org/apache/geode/internal/cache/persistence/DiskStoreID.java

@@ -80,7 +80,7 @@ public class DiskStoreID implements VersionSource<DiskStoreID>, Serializable

{        return 1;      }

     int result = Long.signum(mostSig - tagID.mostSig);

-    if (result != 0) {

+    if (result == 0)

{        result = Long.signum(leastSig - tagID.leastSig);      }

     return result;