From b06e7e60f9152d0d323884818d8c9a9243310051 Mon Sep 17 00:00:00 2001
From: Andy Wilkinson <wilkinsona@vmware.com>
Date: Fri, 30 Jun 2023 14:38:31 +0100
Subject: [PATCH] Polish "Fix asymmetry of equals when element has trailing
 dashes"

See gh-34804
---
 .../source/ConfigurationPropertyName.java     | 19 +++++++++++++++++--
 .../ConfigurationPropertyNameTests.java       | 15 +++++++--------
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java
index a1a3d6b7b1b0..6713e2f2a1eb 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -406,7 +406,7 @@ private boolean dashIgnoringElementEquals(Elements e1, Elements e2, int i) {
 		int i2 = 0;
 		while (i1 < l1) {
 			if (i2 >= l2) {
-				return remainderIsNotAlphanumeric(e1, i, i1);
+				return remainderIsDashes(e1, i, i1);
 			}
 			char ch1 = e1.charAt(i, i1);
 			char ch2 = e2.charAt(i, i2);
@@ -487,6 +487,21 @@ private boolean remainderIsNotAlphanumeric(Elements elements, int element, int i
 		return true;
 	}
 
+	private boolean remainderIsDashes(Elements elements, int element, int index) {
+		if (elements.getType(element).isIndexed()) {
+			return false;
+		}
+		int length = elements.getLength(element);
+		do {
+			char c = Character.toLowerCase(elements.charAt(element, index++));
+			if (c != '-') {
+				return false;
+			}
+		}
+		while (index < length);
+		return true;
+	}
+
 	@Override
 	public int hashCode() {
 		int hashCode = this.hashCode;
diff --git a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameTests.java b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameTests.java
index 2cf37b77a79d..5c29beedebfb 100644
--- a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameTests.java
+++ b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameTests.java
@@ -693,21 +693,20 @@ void equalsWhenNameStartsTheSameUsingDashedCompare() {
 		assertThat(n2).isNotEqualTo(n1);
 	}
 
-	@Test
-	void equalsWhenAdaptedNameMatchesDueToRemovalOfTrailingCharacters() {
-		// gh-30317
+	@Test // gh-30317
+	void equalsWhenAdaptedNameMatchesDueToRemovalOfTrailingNonUniformCharacters() {
 		ConfigurationPropertyName name1 = ConfigurationPropertyName.of("example.demo");
 		ConfigurationPropertyName name2 = ConfigurationPropertyName.adapt("example.demo$$", '.');
 		assertThat(name1).isEqualTo(name2);
 		assertThat(name2).isEqualTo(name1);
 	}
 
-	@Test
-	void equalsSymmetricWhenNameMatchesDueToRemovalOfTrailingDashes() {
-		ConfigurationPropertyName n1 = ConfigurationPropertyName.of("foobar");
-		ConfigurationPropertyName n2 = ConfigurationPropertyName.of("foobar--");
-		assertThat(n1).isEqualTo(n2);
+	@Test // gh-34804
+	void equalsSymmetricWhenNameMatchesDueToIgnoredTrailingDashes() {
+		ConfigurationPropertyName n1 = ConfigurationPropertyName.of("example.demo");
+		ConfigurationPropertyName n2 = ConfigurationPropertyName.of("example.demo--");
 		assertThat(n2).isEqualTo(n1);
+		assertThat(n1).isEqualTo(n2);
 	}
 
 	@Test