Fix StringSequence.equals() for different lengths

See gh-15465

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

@@ -126,7 +126,7 @@ final class StringSequence implements CharSequence {
 			}
 			return true;
 		}
-		return true;
+		return false;
 	}
 
 	@Override

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

@@ -167,6 +167,13 @@ public class StringSequenceTests {
 		assertThat(a).isEqualTo(b).isNotEqualTo(c);
 	}
 
+	@Test
+	public void notEqualsWhenSequencesOfDifferentLength() {
+		StringSequence a = new StringSequence("abcd");
+		StringSequence b = new StringSequence("ef");
+		assertThat(a).isNotEqualTo(b);
+	}
+
 	@Test
 	public void startsWithWhenExactMatch() {
 		assertThat(new StringSequence("abc").startsWith("abc")).isTrue();