SOLR-8240: A request that sends f with mapUniqueKeyOnly=true now fails with a 400 error

changelog/unreleased/SOLR-8240-map-unique-key-only-f-conflict.yml

@@ -0,0 +1,8 @@
+title: >
+  /update/json/docs now rejects field mapping parameters (f) combined with mapUniqueKeyOnly=true with a 400 error instead of silently ignoring the mappings.
+type: changed
+authors:
+  - name: Nick Shanin
+links:
+  - name: SOLR-8240
+    url: https://issues.apache.org/jira/browse/SOLR-8240

solr/core/src/java/org/apache/solr/handler/loader/JsonLoader.java

@@ -246,10 +246,16 @@ void processUpdate(Reader reader) throws IOException {
     private void handleSplitMode(String split, String[] fields, final Reader reader)
         throws IOException {
       if (split == null) split = "/";
+      final boolean mapUniqueKeyOnly = req.getParams().getBool("mapUniqueKeyOnly", false);
+      if (mapUniqueKeyOnly && fields != null && fields.length > 0) {
+        throw new SolrException(
+            SolrException.ErrorCode.BAD_REQUEST,
+            "Field mappings (f) are ignored when mapUniqueKeyOnly=true; set mapUniqueKeyOnly=false"
+                + " to map fields");
+      }
       if (fields == null || fields.length == 0) fields = new String[] {"$FQN:/**"};
       final boolean echo = "true".equals(req.getParams().get("echo"));
       final String srcField = req.getParams().get("srcField");
-      final boolean mapUniqueKeyOnly = req.getParams().getBool("mapUniqueKeyOnly", false);
       if (srcField != null) {
         if (!"/".equals(split))
           throw new SolrException(

solr/core/src/test-files/solr/collection1/conf/solrconfig-update-json-docs-initparams.xml

@@ -0,0 +1,45 @@
+<?xml version="1.0" ?>
+
+<!--
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements.  See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License.  You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+
+<config>
+
+  <dataDir>${solr.data.dir:}</dataDir>
+
+  <directoryFactory name="DirectoryFactory"
+                    class="${solr.directoryFactory:solr.NRTCachingDirectoryFactory}"/>
+  <schemaFactory class="ClassicIndexSchemaFactory"/>
+
+  <luceneMatchVersion>${tests.luceneMatchVersion:LATEST}</luceneMatchVersion>
+
+  <xi:include href="solrconfig.snippet.randomindexconfig.xml" xmlns:xi="http://www.w3.org/2001/XInclude"/>
+
+  <updateHandler class="solr.DirectUpdateHandler2">
+    <commitWithin>
+      <softCommit>${solr.commitwithin.softcommit:true}</softCommit>
+    </commitWithin>
+  </updateHandler>
+
+  <initParams path="/update/json/docs">
+    <lst name="defaults">
+      <bool name="mapUniqueKeyOnly">true</bool>
+      <str name="df">_catch_all</str>
+    </lst>
+  </initParams>
+
+</config>

solr/core/src/test/org/apache/solr/core/TestInitParams.java

@@ -18,9 +18,14 @@
 
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import org.apache.solr.SolrTestCaseJ4;
+import org.apache.solr.common.SolrException;
+import org.apache.solr.common.params.ModifiableSolrParams;
+import org.apache.solr.common.util.ContentStreamBase;
 import org.apache.solr.common.util.NamedList;
+import org.apache.solr.request.SolrQueryRequestBase;
 import org.apache.solr.request.SolrRequestHandler;
 import org.apache.solr.response.SolrQueryResponse;
 import org.junit.BeforeClass;
@@ -127,4 +132,39 @@ public void testMatchPath() {
     assertTrue(initParams.matchPath("/update/json"));
     assertTrue(initParams.matchPath("/update"));
   }
+
+  @Test
+  public void testUpdateJsonDocsInitParamsRejectsFieldMappings() throws Exception {
+    deleteCore();
+    initCore("solrconfig-update-json-docs-initparams.xml", "schema.xml");
+    try {
+      SolrRequestHandler handler = h.getCore().getRequestHandler("/update/json/docs");
+      SolrQueryResponse rsp = new SolrQueryResponse();
+      handler.handleRequest(jsonDocsRequest("f", "title:/title"), rsp);
+      Exception ex = rsp.getException();
+      assertNotNull("expected the handler to record a rejection on the response", ex);
+      assertTrue(ex.toString(), ex instanceof SolrException);
+      assertEquals(SolrException.ErrorCode.BAD_REQUEST.code, ((SolrException) ex).code());
+      assertTrue(ex.getMessage(), ex.getMessage().contains("mapUniqueKeyOnly"));
+
+      rsp = new SolrQueryResponse();
+      handler.handleRequest(
+          jsonDocsRequest("mapUniqueKeyOnly", "false", "echo", "true", "f", "title:/title"), rsp);
+      assertEquals("[{title=t}]", String.valueOf(rsp.getValues().get("docs")));
+    } finally {
+      deleteCore();
+      initCore("solrconfig-paramset.xml", "schema.xml");
+    }
+  }
+
+  private SolrQueryRequestBase jsonDocsRequest(String... keysAndValues) {
+    ModifiableSolrParams solrParams = params("json.command", "false");
+    for (int i = 0; i < keysAndValues.length; i += 2) {
+      solrParams.set(keysAndValues[i], keysAndValues[i + 1]);
+    }
+    SolrQueryRequestBase req = new SolrQueryRequestBase(h.getCore(), solrParams) {};
+    String json = "{\"id\":\"1\",\"title\":\"t\"}";
+    req.setContentStreams(List.of(new ContentStreamBase.StringStream(json, "application/json")));
+    return req;
+  }
 }

solr/core/src/test/org/apache/solr/handler/JsonLoaderTest.java

@@ -189,6 +189,45 @@ public void testInvalidJsonProducesBadRequestSolrException() {
     assertTrue(ex.getMessage().contains("JSON"));
   }
 
+  @Test
+  public void testFieldMappingWithMapUniqueKeyOnlyIsRejected() {
+    String json = "{'id':'1','title':'t'}".replace('\'', '"');
+    SolrQueryResponse rsp = new SolrQueryResponse();
+    BufferingRequestProcessor p = new BufferingRequestProcessor(null);
+    JsonLoader loader = new JsonLoader();
+
+    SolrException ex =
+        expectThrows(
+            SolrException.class,
+            () ->
+                loader.load(
+                    req(
+                        "json.command", "false",
+                        "mapUniqueKeyOnly", "true",
+                        "df", "_catch_all",
+                        "f", "title:/title"),
+                    rsp,
+                    new ContentStreamBase.StringStream(json),
+                    p));
+    assertEquals(SolrException.ErrorCode.BAD_REQUEST.code, ex.code());
+    assertTrue(ex.getMessage(), ex.getMessage().contains("mapUniqueKeyOnly"));
+  }
+
+  @Test
+  public void testFieldMappingWithMapUniqueKeyOnlyFalseIsAccepted() throws Exception {
+    String json = "{'id':'1','title':'t'}".replace('\'', '"');
+    SolrQueryResponse rsp = new SolrQueryResponse();
+    BufferingRequestProcessor p = new BufferingRequestProcessor(null);
+    JsonLoader loader = new JsonLoader();
+    loader.load(
+        req("json.command", "false", "mapUniqueKeyOnly", "false", "f", "title:/title"),
+        rsp,
+        new ContentStreamBase.StringStream(json),
+        p);
+    assertEquals(1, p.addCommands.size());
+    assertEquals("t", p.addCommands.get(0).solrDoc.getFieldValue("title"));
+  }
+
   public void testSimpleFormatInAdd() throws Exception {
     String str = "{'add':[{'id':'1'},{'id':'2'}]}".replace('\'', '"');
     SolrQueryRequest req = req();

solr/solr-ref-guide/modules/indexing-guide/pages/transforming-and-indexing-custom-json.adoc

@@ -65,6 +65,7 @@ Wildcards can be used here, see <<Using Wildcards for Field Names>> below for mo
 This parameter is particularly convenient when the fields in the input JSON are not available in the schema and xref:schemaless-mode.adoc[schemaless mode] is not enabled.
 This will index all the fields into the default search field (using the `df` parameter) and only the `uniqueKey` field is mapped to the corresponding field in the schema.
 If the input JSON does not have a value for the `uniqueKey` field then a UUID is generated for the same.
+Field mapping parameters (`f`) cannot be combined with this parameter: a request that supplies both is rejected with a 400 error, since the mappings would otherwise be silently ignored.
 
 `df`::
 +