Set cookie path to context path without trailing slash

Closes gh-1863

Author: eleftherias

spring-session-core/src/main/java/org/springframework/session/web/http/DefaultCookieSerializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2019 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -432,7 +432,8 @@ private String getDomainName(HttpServletRequest request) {
 
 	private String getCookiePath(HttpServletRequest request) {
 		if (this.cookiePath == null) {
-			return request.getContextPath() + "/";
+			String contextPath = request.getContextPath();
+			return (contextPath != null && contextPath.length() > 0) ? contextPath : "/";
 		}
 		return this.cookiePath;
 	}

spring-session-core/src/test/java/org/springframework/session/web/http/CookieHttpSessionIdResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2019 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -109,7 +109,7 @@ void onNewSessionCookiePath() {
 		this.strategy.setSessionId(this.request, this.response, this.session.getId());
 
 		Cookie sessionCookie = this.response.getCookie(this.cookieName);
-		assertThat(sessionCookie.getPath()).isEqualTo(this.request.getContextPath() + "/");
+		assertThat(sessionCookie.getPath()).isEqualTo(this.request.getContextPath());
 	}
 
 	@Test
@@ -131,7 +131,7 @@ void onDeleteSessionCookiePath() {
 		this.strategy.expireSession(this.request, this.response);
 
 		Cookie sessionCookie = this.response.getCookie(this.cookieName);
-		assertThat(sessionCookie.getPath()).isEqualTo(this.request.getContextPath() + "/");
+		assertThat(sessionCookie.getPath()).isEqualTo(this.request.getContextPath());
 	}
 
 	@Test

spring-session-core/src/test/java/org/springframework/session/web/http/DefaultCookieSerializerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2019 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -267,15 +267,15 @@ void writeCookieCookiePathDefaultEmptyContextPathUsed() {
 	void writeCookieCookiePathDefaultContextPathUsed() {
 		this.request.setContextPath("/context");
 		this.serializer.writeCookieValue(cookieValue(this.sessionId));
-		assertThat(getCookie().getPath()).isEqualTo("/context/");
+		assertThat(getCookie().getPath()).isEqualTo("/context");
 	}
 
 	@Test
 	void writeCookieCookiePathExplicitNullCookiePathContextPathUsed() {
 		this.request.setContextPath("/context");
 		this.serializer.setCookiePath(null);
 		this.serializer.writeCookieValue(cookieValue(this.sessionId));
-		assertThat(getCookie().getPath()).isEqualTo("/context/");
+		assertThat(getCookie().getPath()).isEqualTo("/context");
 	}
 
 	@Test