1 files changed, 16 insertions, 4 deletions
diff --git a/sonar-core/src/main/java/org/sonar/core/issue/tracking/AbstractTracker.java b/sonar-core/src/main/java/org/sonar/core/issue/tracking/AbstractTracker.java
index feb29d55599..406edb821b4 100644
--- a/sonar-core/src/main/java/org/sonar/core/issue/tracking/AbstractTracker.java
+++ b/sonar-core/src/main/java/org/sonar/core/issue/tracking/AbstractTracker.java
@@ -113,10 +113,13 @@ public class AbstractTracker<RAW extends Trackable, BASE extends Trackable> {
     }
 
     @Override
-    public boolean equals(@Nonnull Object o) {
+    public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
+      if (o == null || getClass() != o.getClass()) {
+        return false;
+      }
       LineAndLineHashAndMessage that = (LineAndLineHashAndMessage) o;
       // start with most discriminant field
       return Objects.equals(line, that.line)
@@ -143,10 +146,13 @@ public class AbstractTracker<RAW extends Trackable, BASE extends Trackable> {
     }
 
     @Override
-    public boolean equals(@Nonnull Object o) {
+    public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
+      if (o == null || getClass() != o.getClass()) {
+        return false;
+      }
       LineHashAndMessageKey that = (LineHashAndMessageKey) o;
       // start with most discriminant field
       return lineHash.equals(that.lineHash)
@@ -172,10 +178,13 @@ public class AbstractTracker<RAW extends Trackable, BASE extends Trackable> {
     }
 
     @Override
-    public boolean equals(@Nonnull Object o) {
+    public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
+      if (o == null || getClass() != o.getClass()) {
+        return false;
+      }
       LineAndMessageKey that = (LineAndMessageKey) o;
       // start with most discriminant field
       return Objects.equals(line, that.line)
@@ -199,10 +208,13 @@ public class AbstractTracker<RAW extends Trackable, BASE extends Trackable> {
     }
 
     @Override
-    public boolean equals(@Nonnull Object o) {
+    public boolean equals(Object o) {
       if (this == o) {
         return true;
       }
+      if (o == null || getClass() != o.getClass()) {
+        return false;
+      }
       LineHashKey that = (LineHashKey) o;
       // start with most discriminant field
       return lineHash.equals(that.lineHash)