Adds percent-encoding for Location headers (#21057)

This should cause unicode elements in the location header to be percent-encoded, instead of being left alone.

Closes #21016

core/src/main/java/org/elasticsearch/action/DocWriteResponse.java

@@ -35,6 +35,8 @@ import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.rest.RestStatus;
 
 import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
 import java.util.Locale;
 
 /**
@@ -186,8 +188,9 @@ public abstract class DocWriteResponse extends ReplicationResponse implements Wr
     /**
      * Gets the location of the written document as a string suitable for a {@code Location} header.
      * @param routing any routing used in the request. If null the location doesn't include routing information.
+     *
      */
-    public String getLocation(@Nullable String routing) {
+    public String getLocation(@Nullable String routing) throws URISyntaxException {
         // Absolute path for the location of the document. This should be allowed as of HTTP/1.1:
         // https://tools.ietf.org/html/rfc7231#section-7.1.2
         String index = getIndex();
@@ -205,7 +208,9 @@ public abstract class DocWriteResponse extends ReplicationResponse implements Wr
         if (routing != null) {
             location.append(routingStart).append(routing);
         }
-        return location.toString();
+
+        URI uri = new URI(location.toString());
+        return uri.toASCIIString();
     }
 
     @Override

core/src/main/java/org/elasticsearch/rest/action/document/RestIndexAction.java

@@ -32,6 +32,7 @@ import org.elasticsearch.rest.action.RestActions;
 import org.elasticsearch.rest.action.RestStatusToXContentListener;
 
 import java.io.IOException;
+import java.net.URISyntaxException;
 
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 import static org.elasticsearch.rest.RestRequest.Method.PUT;
@@ -82,7 +83,14 @@ public class RestIndexAction extends BaseRestHandler {
         }
 
         return channel ->
-            client.index(indexRequest, new RestStatusToXContentListener<>(channel, r -> r.getLocation(indexRequest.routing())));
+            client.index(indexRequest, new RestStatusToXContentListener<>(channel, r -> {
+                try {
+                    return r.getLocation(indexRequest.routing());
+                } catch (URISyntaxException ex) {
+                    logger.warn("Location string is not a valid URI.", ex);
+                    return null;
+                }
+            }));
     }
 
 }

core/src/main/java/org/elasticsearch/rest/action/document/RestUpdateAction.java

@@ -37,6 +37,7 @@ import org.elasticsearch.rest.action.RestStatusToXContentListener;
 import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
 
 import java.io.IOException;
+import java.net.URISyntaxException;
 
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
@@ -99,6 +100,13 @@ public class RestUpdateAction extends BaseRestHandler {
         });
 
         return channel ->
-            client.update(updateRequest, new RestStatusToXContentListener<>(channel, r -> r.getLocation(updateRequest.routing())));
+            client.update(updateRequest, new RestStatusToXContentListener<>(channel, r -> {
+                try {
+                    return r.getLocation(updateRequest.routing());
+                } catch (URISyntaxException ex) {
+                    logger.warn("Location string is not a valid URI.", ex);
+                    return null;
+                }
+            }));
     }
 }

core/src/test/java/org/elasticsearch/action/DocWriteResponseTests.java

@@ -30,13 +30,14 @@ import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.test.ESTestCase;
 
 import java.io.IOException;
+import java.net.URISyntaxException;
 
 import static org.hamcrest.Matchers.hasEntry;
 import static org.hamcrest.Matchers.hasKey;
 import static org.hamcrest.Matchers.not;
 
 public class DocWriteResponseTests extends ESTestCase {
-    public void testGetLocation() {
+    public void testGetLocation() throws URISyntaxException {
         DocWriteResponse response =
             new DocWriteResponse(
                 new ShardId("index", "uuid", 0),
@@ -51,6 +52,35 @@ public class DocWriteResponseTests extends ESTestCase {
         assertEquals("/index/type/id?routing=test_routing", response.getLocation("test_routing"));
     }
 
+    public void testGetLocationNonAscii() throws URISyntaxException {
+        DocWriteResponse response =
+            new DocWriteResponse(
+                new ShardId("index", "uuid", 0),
+                "type",
+                "❤",
+                SequenceNumbersService.UNASSIGNED_SEQ_NO,
+                0,
+                Result.CREATED) {
+            };
+        assertEquals("/index/type/%E2%9D%A4", response.getLocation(null));
+        assertEquals("/index/type/%E2%9D%A4?routing=%C3%A4", response.getLocation("%C3%A4"));
+    }
+
+    public void testInvalidGetLocation() {
+        String invalidPath = "!^*$(@!^!#@";
+        DocWriteResponse invalid =
+            new DocWriteResponse(
+                new ShardId("index", "uuid", 0),
+                "type",
+                invalidPath,
+                SequenceNumbersService.UNASSIGNED_SEQ_NO,
+                0,
+                Result.CREATED) {
+            };
+        Throwable exception = expectThrows(URISyntaxException.class, () -> invalid.getLocation(null));
+        assertTrue(exception.getMessage().contains(invalidPath));
+    }
+
     /**
      * Tests that {@link DocWriteResponse#toXContent(XContentBuilder, ToXContent.Params)} doesn't include {@code forced_refresh} unless it
      * is true. We can't assert this in the yaml tests because "not found" is also "false" there....