Fix EndpointRequest.toLinks() not matching when base-path is '/'

When management.endpoints.web.base-path is set to "/",
cleanBasePath() stripped it to "", making LinksRequestMatcher
return EMPTY_MATCHER (always false). Preserve "/" as a valid
base path and avoid producing "//" patterns in link matchers.

Fixes gh-34834

Author: apoorvdarshan

module/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/WebEndpointProperties.java

@@ -67,7 +67,7 @@ public void setBasePath(String basePath) {
 	}
 
 	private String cleanBasePath(String basePath) {
-		if (StringUtils.hasText(basePath) && basePath.endsWith("/")) {
+		if (StringUtils.hasText(basePath) && basePath.endsWith("/") && basePath.length() > 1) {
 			return basePath.substring(0, basePath.length() - 1);
 		}
 		return basePath;

module/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/WebEndpointPropertiesTests.java

@@ -38,7 +38,7 @@ void defaultBasePathShouldBeApplication() {
 	void basePathShouldBeCleaned() {
 		WebEndpointProperties properties = new WebEndpointProperties();
 		properties.setBasePath("/");
-		assertThat(properties.getBasePath()).isEmpty();
+		assertThat(properties.getBasePath()).isEqualTo("/");
 		properties.setBasePath("/actuator/");
 		assertThat(properties.getBasePath()).isEqualTo("/actuator");
 	}

module/spring-boot-security/src/main/java/org/springframework/boot/security/autoconfigure/actuate/web/reactive/EndpointRequest.java

@@ -371,9 +371,13 @@ private LinksServerWebExchangeMatcher() {
 		@Override
 		protected ServerWebExchangeMatcher createDelegate(WebEndpointProperties properties) {
 			if (StringUtils.hasText(properties.getBasePath())) {
+				String basePath = properties.getBasePath();
+				if (basePath.endsWith("/")) {
+					return new PathPatternParserServerWebExchangeMatcher(basePath);
+				}
 				return new OrServerWebExchangeMatcher(
-						new PathPatternParserServerWebExchangeMatcher(properties.getBasePath()),
-						new PathPatternParserServerWebExchangeMatcher(properties.getBasePath() + "/"));
+						new PathPatternParserServerWebExchangeMatcher(basePath),
+						new PathPatternParserServerWebExchangeMatcher(basePath + "/"));
 			}
 			return EMPTY_MATCHER;
 		}

module/spring-boot-security/src/main/java/org/springframework/boot/security/autoconfigure/actuate/web/servlet/EndpointRequest.java

@@ -227,7 +227,9 @@ protected List<RequestMatcher> getLinksMatchers(RequestMatcherFactory requestMat
 				RequestMatcherProvider matcherProvider, String basePath) {
 			List<RequestMatcher> linksMatchers = new ArrayList<>();
 			linksMatchers.add(requestMatcherFactory.antPath(matcherProvider, null, basePath));
-			linksMatchers.add(requestMatcherFactory.antPath(matcherProvider, null, basePath, "/"));
+			if (!basePath.endsWith("/")) {
+				linksMatchers.add(requestMatcherFactory.antPath(matcherProvider, null, basePath, "/"));
+			}
 			return linksMatchers;
 		}
 

module/spring-boot-security/src/test/java/org/springframework/boot/security/autoconfigure/actuate/web/reactive/EndpointRequestTests.java

@@ -145,6 +145,14 @@ void toLinksWhenBasePathEmptyShouldNotMatch() {
 		assertMatcher.doesNotMatch("/");
 	}
 
+	@Test
+	void toLinksWhenBasePathIsRootShouldMatch() {
+		ServerWebExchangeMatcher matcher = EndpointRequest.toLinks();
+		RequestMatcherAssert assertMatcher = assertMatcher(matcher, "/");
+		assertMatcher.matches("/");
+		assertMatcher.doesNotMatch("/foo");
+	}
+
 	@Test
 	void excludeByClassShouldNotMatchExcluded() {
 		ServerWebExchangeMatcher matcher = EndpointRequest.toAnyEndpoint()

module/spring-boot-security/src/test/java/org/springframework/boot/security/autoconfigure/actuate/web/servlet/EndpointRequestTests.java

@@ -151,6 +151,14 @@ void toLinksWhenBasePathEmptyShouldNotMatch() {
 		assertMatcher.doesNotMatch("/");
 	}
 
+	@Test
+	void toLinksWhenBasePathIsRootShouldMatch() {
+		RequestMatcher matcher = EndpointRequest.toLinks();
+		RequestMatcherAssert assertMatcher = assertMatcher(matcher, "/");
+		assertMatcher.matches("/");
+		assertMatcher.doesNotMatch("/foo");
+	}
+
 	@Test
 	void excludeByClassShouldNotMatchExcluded() {
 		RequestMatcher matcher = EndpointRequest.toAnyEndpoint().excluding(FooEndpoint.class, BazServletEndpoint.class);