From f29577330a088ce3d941b6744c56bb87c2f5f958 Mon Sep 17 00:00:00 2001
From: finnetrolle <maxsyachin@gmail.com>
Date: Tue, 20 Aug 2019 00:08:39 +0300
Subject: [PATCH] #1028 Remove query template empty argument filtering to allow
 empty values

---
 .../main/java/feign/template/QueryTemplate.java   |  1 -
 core/src/test/java/feign/FeignTest.java           | 15 +++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/core/src/main/java/feign/template/QueryTemplate.java b/core/src/main/java/feign/template/QueryTemplate.java
index c67735272..7abf34cf8 100644
--- a/core/src/main/java/feign/template/QueryTemplate.java
+++ b/core/src/main/java/feign/template/QueryTemplate.java
@@ -72,7 +72,6 @@ public static QueryTemplate create(String name,
 
     /* remove all empty values from the array */
     Collection<String> remaining = StreamSupport.stream(values.spliterator(), false)
-        .filter(Util::isNotBlank)
         .collect(Collectors.toList());
 
     StringBuilder template = new StringBuilder();
diff --git a/core/src/test/java/feign/FeignTest.java b/core/src/test/java/feign/FeignTest.java
index 0a8b1ab02..ca988b2c9 100644
--- a/core/src/test/java/feign/FeignTest.java
+++ b/core/src/test/java/feign/FeignTest.java
@@ -53,6 +53,18 @@ public class FeignTest {
   @Rule
   public final MockWebServer server = new MockWebServer();
 
+  @Test
+  public void emptyQueryArrayParameter() throws Exception {
+    server.enqueue(new MockResponse().setBody("foo"));
+
+    TestInterface api = new TestInterfaceBuilder().target("http://localhost:" + server.getPort());
+
+    api.emptyArrayElement(Arrays.asList("first", "", "third"));
+
+    assertThat(server.takeRequest())
+            .hasPath("/test?people=first&people=&people=third");
+  }
+
   @Test
   public void iterableQueryParams() throws Exception {
     server.enqueue(new MockResponse().setBody("foo"));
@@ -938,6 +950,9 @@ void form(
               @Param("user_name") String user,
               @Param("password") String password);
 
+    @RequestLine("GET /test?people={people}")
+    Response emptyArrayElement(@Param(value = "people", encoded = true) Collection<String> people);
+
     @RequestLine("GET /{1}/{2}")
     Response uriParam(@Param("1") String one, URI endpoint, @Param("2") String two);