fix(VariableAccessFilter): ensure all accesses are returned for gener…

…ic fields #5391

src/main/java/spoon/reflect/visitor/filter/VariableAccessFilter.java

@@ -12,16 +12,15 @@
 import spoon.reflect.visitor.Filter;
 
 /**
- * This simple filter matches all the accesses to a given field.
+ * This simple filter matches all the accesses to a given variable.
  */
 public class VariableAccessFilter<T extends CtVariableAccess<?>> implements Filter<T> {
 	CtVariableReference<?> variable;
 
 	/**
-	 * Creates a new field access filter.
+	 * Creates a new variable access filter.
 	 *
-	 * @param variable
-	 * 		the accessed variable
+	 * @param variable the variable to find accesses to, must not be {@code null}
 	 */
 	public VariableAccessFilter(CtVariableReference<?> variable) {
 		if (variable == null) {
@@ -32,7 +31,20 @@ public VariableAccessFilter(CtVariableReference<?> variable) {
 
 	@Override
 	public boolean matches(T variableAccess) {
-		return variable.equals(variableAccess.getVariable());
+		return this.variable.equals(variableAccess.getVariable())
+			// if this.variable is a reference to a generic field, then the reference of the variableAccess might not
+			// be equal.
+			//
+			// For example:
+			//
+			// Given class A<T> { T t }, the reference would be to `T t`,
+			// but an access to `t` could look like this:
+			// `A<String> a = new A<>(); a.t = "foo";`
+			//                           ^^^ reference to `String t`
+			// => (String t) != (T t), but the same variable is accessed
+			//    Therefore, it is checked that the variable they are referencing is the same.
+			|| this.variable.getDeclaration() != null
+			&& this.variable.getDeclaration().equals(variableAccess.getVariable().getDeclaration());
 	}
 
 }