Fix using limit=0 and details=on to get only the count of elements #1492

CHANGES_NEXT_RELEASE

@@ -1,3 +1,4 @@
+- Fix: Using limit=0 and options=count to get only the count of elements (#1492)
 - Add: maxFailsLimit subscription field, so subscription is automatically passed to inactive after that number of failed notification attemps (#3541)
 - Add: failsCounter subscription field, to count the number of consecutive notificaitons fails (#3541)
 - Fix: throttling misbehaviour after subscription update when csubs cache is in use (#3981)

src/lib/rest/rest.cpp

@@ -177,9 +177,7 @@ static int uriArgumentGet(void* cbDataP, MHD_ValueKind kind, const char* ckey, c
     }
     else if (limit == 0)
     {
-      OrionError error(SccBadRequest, std::string("Bad pagination limit: /") + value + "/ [a value of ZERO is unacceptable]");
-      ciP->httpStatusCode = error.code;
-      ciP->answer         = error.smartRender(ciP->apiVersion);
+      ciP->httpStatusCode = SccOk;
       return MHD_YES;
     }
   }

test/functionalTest/cases/0000_bad_requests/pagination_error_in_uri_params.test

@@ -93,16 +93,16 @@ Date: REGEX(.*)
 
 
 +++++ 3. URI param 'limit' == 0
-HTTP/1.1 400 Bad Request
-Content-Length: 135
+HTTP/1.1 200 OK
+Content-Length: 86
 Content-Type: application/json
 Fiware-Correlator: REGEX([0-9a-f\-]{36})
 Date: REGEX(.*)
 
 {
-    "orionError": {
+    "errorCode": {
         "code": "400",
-        "details": "Bad pagination limit: /000000/ [a value of ZERO is unacceptable]",
+        "details": "JSON Parse Error",
         "reasonPhrase": "Bad Request"
     }
 }

test/functionalTest/cases/1492_using_limit=0_and_options=count_to_get_only_the_count_of_elements/using_limit=0_and_options=count_to_get_only_the_count_of_elements.test

@@ -0,0 +1,79 @@
+# Copyright 2021 Telefonica Investigacion y Desarrollo, S.A.U
+#
+# This file is part of Orion Context Broker.
+#
+# Orion Context Broker is free software: you can redistribute it and/or
+# modify it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# Orion Context Broker is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with Orion Context Broker. If not, see http://www.gnu.org/licenses/.
+#
+# For those usages not covered by this license please contact with
+# iot_support at tid dot es
+
+# VALGRIND_READY - to mark the test ready for valgrindTestSuite.sh
+
+--NAME--
+using_limit=0_and_options=count_to_get_only_the_count_of_elements
+
+--SHELL-INIT--
+dbInit CB
+brokerStart CB
+
+--SHELL--
+
+#
+# 01. GET /v2/entities with 'limit' == 0 and options=count
+# 02. GET /v2/entities with 'limit' == 0
+#
+
+echo "01. GET /v2/entities with 'limit' == 0 and options=count"
+echo "========================================================"
+orionCurl --url "/v2/entities?limit=0&options=count"
+echo
+echo
+
+
+
+echo "02. GET /v2/entities with 'limit' == 0"
+echo "======================================"
+orionCurl --url "/v2/entities?limit=0"
+echo
+echo
+
+
+
+--REGEXPECT--
+01. GET /v2/entities with 'limit' == 0 and options=count
+========================================================
+HTTP/1.1 200 OK
+Content-Length: 2
+Content-Type: application/json
+Fiware-Total-Count: 0
+Fiware-Correlator: REGEX([0-9a-f\-]{36})
+Date: REGEX(.*)
+
+[]
+
+
+02. GET /v2/entities with 'limit' == 0
+======================================
+HTTP/1.1 200 OK
+Content-Length: 2
+Content-Type: application/json
+Fiware-Correlator: REGEX([0-9a-f\-]{36})
+Date: REGEX(.*)
+
+[]
+
+
+--TEARDOWN--
+brokerStop CB
+dbDrop CB