AVRO-4202: Refer to fields for generated hashCode (#3547)

The generated hashCode function has a local parameter called result.
To prevent this local variable to conflict with field which have the
same name, it has to refer to the fields with `this.<fieldName>` making
it unambiguous refer to fields and not local variables.

Author: steven-aerts

lang/java/compiler/src/main/velocity/org/apache/avro/compiler/specific/templates/java/classic/record.vm

@@ -624,7 +624,7 @@ public class ${this.mangleTypeIdentifier($schema.getName())} extends ${this.getS
 #foreach ($field in $schema.getFields())
 #if (!${this.ignoredField($field)})
 #set ($n = ${this.mangle($field.name(), $schema.isError())})
-    result = 31 * result + ${this.hashCodeFor($field.schema(), $n)};
+    result = 31 * result + ${this.hashCodeFor($field.schema(), "this." + $n)};
 #end
 #end
     return result;

lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/FieldTest.java

@@ -665,12 +665,12 @@ public FieldTest build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + Integer.hashCode(number);
-    result = 31 * result + (last_name == null ? 0 : last_name.hashCode());
-    result = 31 * result + (timestamp == null ? 0 : timestamp.hashCode());
-    result = 31 * result + (timestampMicros == null ? 0 : timestampMicros.hashCode());
-    result = 31 * result + (timeMillis == null ? 0 : timeMillis.hashCode());
-    result = 31 * result + (timeMicros == null ? 0 : timeMicros.hashCode());
+    result = 31 * result + Integer.hashCode(this.number);
+    result = 31 * result + (this.last_name == null ? 0 : this.last_name.hashCode());
+    result = 31 * result + (this.timestamp == null ? 0 : this.timestamp.hashCode());
+    result = 31 * result + (this.timestampMicros == null ? 0 : this.timestampMicros.hashCode());
+    result = 31 * result + (this.timeMillis == null ? 0 : this.timeMillis.hashCode());
+    result = 31 * result + (this.timeMicros == null ? 0 : this.timeMicros.hashCode());
     return result;
   }
 

lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JSpecifyNullSafeAnnotationsFieldsTest.java

@@ -585,10 +585,10 @@ public JSpecifyNullSafeAnnotationsFieldsTest build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + (name == null ? 0 : name.hashCode());
-    result = 31 * result + (nullable_name == null ? 0 : nullable_name.hashCode());
-    result = 31 * result + Integer.hashCode(favorite_number);
-    result = 31 * result + (nullable_favorite_number == null ? 0 : nullable_favorite_number.hashCode());
+    result = 31 * result + (this.name == null ? 0 : this.name.hashCode());
+    result = 31 * result + (this.nullable_name == null ? 0 : this.nullable_name.hashCode());
+    result = 31 * result + Integer.hashCode(this.favorite_number);
+    result = 31 * result + (this.nullable_favorite_number == null ? 0 : this.nullable_favorite_number.hashCode());
     return result;
   }
 

lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/JetBrainsNullSafeAnnotationsFieldsTest.java

@@ -585,10 +585,10 @@ public JetBrainsNullSafeAnnotationsFieldsTest build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + (name == null ? 0 : name.hashCode());
-    result = 31 * result + (nullable_name == null ? 0 : nullable_name.hashCode());
-    result = 31 * result + Integer.hashCode(favorite_number);
-    result = 31 * result + (nullable_favorite_number == null ? 0 : nullable_favorite_number.hashCode());
+    result = 31 * result + (this.name == null ? 0 : this.name.hashCode());
+    result = 31 * result + (this.nullable_name == null ? 0 : this.nullable_name.hashCode());
+    result = 31 * result + Integer.hashCode(this.favorite_number);
+    result = 31 * result + (this.nullable_favorite_number == null ? 0 : this.nullable_favorite_number.hashCode());
     return result;
   }
 

lang/java/tools/src/test/compiler/output-string/avro/examples/baseball/Player.java

@@ -593,10 +593,10 @@ public Player build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + Integer.hashCode(number);
-    result = 31 * result + (first_name == null ? 0 : first_name.hashCode());
-    result = 31 * result + (last_name == null ? 0 : last_name.hashCode());
-    result = 31 * result + (position == null ? 0 : position.hashCode());
+    result = 31 * result + Integer.hashCode(this.number);
+    result = 31 * result + (this.first_name == null ? 0 : this.first_name.hashCode());
+    result = 31 * result + (this.last_name == null ? 0 : this.last_name.hashCode());
+    result = 31 * result + (this.position == null ? 0 : this.position.hashCode());
     return result;
   }
 

lang/java/tools/src/test/compiler/output/AddExtraOptionalGettersTest.java

@@ -434,8 +434,8 @@ public AddExtraOptionalGettersTest build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + (name == null ? 0 : name.hashCode());
-    result = 31 * result + (favorite_number == null ? 0 : favorite_number.hashCode());
+    result = 31 * result + (this.name == null ? 0 : this.name.hashCode());
+    result = 31 * result + (this.favorite_number == null ? 0 : this.favorite_number.hashCode());
     return result;
   }
 

lang/java/tools/src/test/compiler/output/NoSettersTest.java

@@ -392,8 +392,8 @@ public NoSettersTest build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + (name == null ? 0 : name.hashCode());
-    result = 31 * result + (favorite_number == null ? 0 : favorite_number.hashCode());
+    result = 31 * result + (this.name == null ? 0 : this.name.hashCode());
+    result = 31 * result + (this.favorite_number == null ? 0 : this.favorite_number.hashCode());
     return result;
   }
 

lang/java/tools/src/test/compiler/output/OptionalGettersAllFieldsTest.java

@@ -497,10 +497,10 @@ public OptionalGettersAllFieldsTest build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + (name == null ? 0 : name.hashCode());
-    result = 31 * result + (nullable_name == null ? 0 : nullable_name.hashCode());
-    result = 31 * result + (favorite_number == null ? 0 : favorite_number.hashCode());
-    result = 31 * result + (nullable_favorite_number == null ? 0 : nullable_favorite_number.hashCode());
+    result = 31 * result + (this.name == null ? 0 : this.name.hashCode());
+    result = 31 * result + (this.nullable_name == null ? 0 : this.nullable_name.hashCode());
+    result = 31 * result + (this.favorite_number == null ? 0 : this.favorite_number.hashCode());
+    result = 31 * result + (this.nullable_favorite_number == null ? 0 : this.nullable_favorite_number.hashCode());
     return result;
   }
 

lang/java/tools/src/test/compiler/output/OptionalGettersNullableFieldsTest.java

@@ -569,11 +569,11 @@ public OptionalGettersNullableFieldsTest build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + (name == null ? 0 : name.hashCode());
-    result = 31 * result + (nullable_name == null ? 0 : nullable_name.hashCode());
-    result = 31 * result + (favorite_number == null ? 0 : favorite_number.hashCode());
-    result = 31 * result + (nullable_favorite_number == null ? 0 : nullable_favorite_number.hashCode());
-    result = 31 * result + (nullable_array == null ? 0 : nullable_array.hashCode());
+    result = 31 * result + (this.name == null ? 0 : this.name.hashCode());
+    result = 31 * result + (this.nullable_name == null ? 0 : this.nullable_name.hashCode());
+    result = 31 * result + (this.favorite_number == null ? 0 : this.favorite_number.hashCode());
+    result = 31 * result + (this.nullable_favorite_number == null ? 0 : this.nullable_favorite_number.hashCode());
+    result = 31 * result + (this.nullable_array == null ? 0 : this.nullable_array.hashCode());
     return result;
   }
 

lang/java/tools/src/test/compiler/output/Player.java

@@ -593,10 +593,10 @@ public Player build() {
   @Override
   public int hashCode() {
     int result = 1;
-    result = 31 * result + Integer.hashCode(number);
-    result = 31 * result + (first_name == null ? 0 : first_name.hashCode());
-    result = 31 * result + (last_name == null ? 0 : last_name.hashCode());
-    result = 31 * result + (position == null ? 0 : position.hashCode());
+    result = 31 * result + Integer.hashCode(this.number);
+    result = 31 * result + (this.first_name == null ? 0 : this.first_name.hashCode());
+    result = 31 * result + (this.last_name == null ? 0 : this.last_name.hashCode());
+    result = 31 * result + (this.position == null ? 0 : this.position.hashCode());
     return result;
   }