Unnecessary null check before instanceof removed

src/org/jetbrains/java/decompiler/struct/consts/LinkConstant.java

@@ -63,7 +63,7 @@ public class LinkConstant extends PooledConstant {
   @Override
   public boolean equals(Object o) {
     if (o == this) return true;
-    if (o == null || !(o instanceof LinkConstant)) return false;
+    if (!(o instanceof LinkConstant)) return false;
 
     LinkConstant cn = (LinkConstant)o;
     return this.type == cn.type &&

src/org/jetbrains/java/decompiler/struct/consts/PrimitiveConstant.java

@@ -40,7 +40,7 @@ public class PrimitiveConstant extends PooledConstant {
   @Override
   public boolean equals(Object o) {
     if (o == this) return true;
-    if (o == null || !(o instanceof PrimitiveConstant)) return false;
+    if (!(o instanceof PrimitiveConstant)) return false;
 
     PrimitiveConstant cn = (PrimitiveConstant)o;
     return this.type == cn.type &&

src/org/jetbrains/java/decompiler/struct/gen/FieldDescriptor.java

@@ -36,7 +36,7 @@ public class FieldDescriptor {
   @Override
   public boolean equals(Object o) {
     if (o == this) return true;
-    if (o == null || !(o instanceof FieldDescriptor)) return false;
+    if (!(o instanceof FieldDescriptor)) return false;
 
     FieldDescriptor fd = (FieldDescriptor)o;
     return type.equals(fd.type);

src/org/jetbrains/java/decompiler/struct/gen/MethodDescriptor.java

@@ -114,7 +114,7 @@ public class MethodDescriptor {
   @Override
   public boolean equals(Object o) {
     if (o == this) return true;
-    if (o == null || !(o instanceof MethodDescriptor)) return false;
+    if (!(o instanceof MethodDescriptor)) return false;
 
     MethodDescriptor md = (MethodDescriptor)o;
     return ret.equals(md.ret) && Arrays.equals(params, md.params);

src/org/jetbrains/java/decompiler/struct/gen/VarType.java

@@ -265,7 +265,7 @@ public class VarType {  // TODO: optimize switch
       return true;
     }
 
-    if (o == null || !(o instanceof VarType)) {
+    if (!(o instanceof VarType)) {
       return false;
     }