SOLR-11231: Guard against unset fields when performing language detection. This closes #232

solr/CHANGES.txt

@@ -105,6 +105,9 @@ Bug Fixes
 
 * SOLR-11619: V2 requests that needed to be forwarded to other nodes would get an NPE. (David Smiley)
 
+* SOLR-11231: Guard against unset fields when performing language detection.
+  (Chris Beer via Steve Rowe)
+
 Optimizations
 ----------------------
 * SOLR-11285: Refactor autoscaling framework to avoid direct references to Zookeeper and Solr

solr/contrib/langid/src/java/org/apache/solr/update/processor/TikaLanguageIdentifierUpdateProcessor.java

@@ -112,13 +112,21 @@ public class TikaLanguageIdentifierUpdateProcessor extends LanguageIdentifierUpd
   private int getExpectedSize(SolrInputDocument doc, String[] fields) {
     int docSize = 0;
     for (String field : fields) {
+      if (doc.containsKey(field)) {
         Collection<Object> contents = doc.getFieldValues(field);
+        if (contents != null) {
           for (Object content : contents) {
             if (content instanceof String) {
               docSize += Math.min(((String) content).length(), maxFieldValueChars);
             }
           }
-      docSize = Math.min(docSize, maxTotalChars);
+
+          if (docSize > maxTotalChars) {
+            docSize = maxTotalChars;
+            break;
+          }
+        }
+      }
     }
     return docSize;
   }

solr/contrib/langid/src/test/org/apache/solr/update/processor/LanguageIdentifierUpdateProcessorFactoryTestCase.java

@@ -211,6 +211,19 @@ public abstract class LanguageIdentifierUpdateProcessorFactoryTestCase extends S
     assertEquals("", liProcessor.process(doc).getFieldValue("language"));
   }
 
+  @Test
+  public void testMissingFieldEmptyString() throws Exception {
+    SolrInputDocument doc;
+    ModifiableSolrParams parameters = new ModifiableSolrParams();
+    parameters.add("langid.fl", "no_such_field");
+    parameters.add("langid.langField", "language");
+    parameters.add("langid.enforceSchema", "false");
+    liProcessor = createLangIdProcessor(parameters);
+
+    doc = new SolrInputDocument();
+    assertEquals("", liProcessor.process(doc).getFieldValue("language"));
+  }
+
   @Test
   public void testFallback() throws Exception {
     SolrInputDocument doc;