Polish "Fix StringSequence.equals() for different lengths"

Closes spring-projectsgh-15465

Author: snicoll

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/StringSequence.java

@@ -111,22 +111,22 @@ public boolean equals(Object obj) {
 if (this == obj) {
 return true;
 }
-if (obj == null || !CharSequence.class.isInstance(obj)) {
+if (!(obj instanceof CharSequence)) {
 return false;
 }
 CharSequence other = (CharSequence) obj;
 int n = length();
-if (n == other.length()) {
-int i = 0;
-while (n-- != 0) {
-if (charAt(i) != other.charAt(i)) {
-return false;
-}
-i++;
+if (n != other.length()) {
+return false;
+}
+int i = 0;
+while (n-- != 0) {
+if (charAt(i) != other.charAt(i)) {
+return false;
 }
-return true;
+i++;
 }
-return false;
+return true;
 }
 
 @Override

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/StringSequenceTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.