Wildcard field bug fix for prefix + term queries. Wildcard syntax should not be supported. (#62085) (#62154)

Wildcard field bug fix for term and prefix queries.
We now escape any * or ? characters in the search string before delegating to the main wildcardQuery() method.

Closes #62081

x-pack/plugin/src/test/resources/rest-api-spec/test/wildcard/10_wildcard_basic.yml

@@ -250,7 +250,7 @@ setup:
           query:
             prefix:
               my_wildcard:
-                value: "hell*"
+                value: "hell"
 
 
   - match: {hits.total.value: 1}

x-pack/plugin/wildcard/src/main/java/org/elasticsearch/xpack/wildcard/mapper/WildcardFieldMapper.java

@@ -844,12 +844,28 @@ public class WildcardFieldMapper extends FieldMapper {
 
         @Override
         public Query termQuery(Object value, QueryShardContext context) {
-            return wildcardQuery(BytesRefs.toString(value), MultiTermQuery.CONSTANT_SCORE_REWRITE, context);
+            String searchTerm = BytesRefs.toString(value);
+            return wildcardQuery(escapeWildcardSyntax(searchTerm),  MultiTermQuery.CONSTANT_SCORE_REWRITE, context);
+        }
+        
+        private String escapeWildcardSyntax(String term) {
+            StringBuilder result = new StringBuilder();
+            for (int i = 0; i < term.length();) {
+                final int c = term.codePointAt(i);
+                int length = Character.charCount(c);
+                // Escape any reserved characters
+                if (c == WildcardQuery.WILDCARD_STRING || c == WildcardQuery.WILDCARD_CHAR || c == WildcardQuery.WILDCARD_ESCAPE) {
+                    result.append("\\");
+                }
+                result.appendCodePoint(c);
+                i += length;
+            }
+            return result.toString();
         }
 
         @Override
         public Query prefixQuery(String value, MultiTermQuery.RewriteMethod method, QueryShardContext context) {
-            return wildcardQuery(value + "*", method, context);
+            return wildcardQuery(escapeWildcardSyntax(value) + "*", method, context);
         }
 
         @Override

x-pack/plugin/wildcard/src/test/java/org/elasticsearch/xpack/wildcard/mapper/WildcardFieldMapperTests.java

@@ -178,6 +178,47 @@ public class WildcardFieldMapperTests extends ESTestCase {
         reader.close();
         dir.close();
     }
+    
+    
+    public void testTermAndPrefixQueryIgnoreWildcardSyntax() throws IOException {
+        Directory dir = newDirectory();
+        IndexWriterConfig iwc = newIndexWriterConfig(WildcardFieldMapper.WILDCARD_ANALYZER);
+        iwc.setMergePolicy(newTieredMergePolicy(random()));
+        RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwc);
+
+        Document doc = new Document();
+        ParseContext.Document parseDoc = new ParseContext.Document();
+        addFields(parseDoc, doc, "f*oo?");
+        indexDoc(parseDoc, doc, iw);
+
+        iw.forceMerge(1);
+        DirectoryReader reader = iw.getReader();
+        IndexSearcher searcher = newSearcher(reader);
+        iw.close();
+        
+        expectTermMatch(searcher, "f*oo*", 0);
+        expectTermMatch(searcher, "f*oo?", 1);
+        expectTermMatch(searcher, "*oo?", 0);
+
+        expectPrefixMatch(searcher, "f*o", 1);
+        expectPrefixMatch(searcher, "f*oo?", 1);
+        expectPrefixMatch(searcher, "f??o", 0);
+        
+        reader.close();
+        dir.close();
+    }
+    
+    private void expectTermMatch(IndexSearcher searcher, String term,long count) throws IOException {
+        Query q = wildcardFieldType.fieldType().termQuery(term, MOCK_QSC);
+        TopDocs td = searcher.search(q, 10, Sort.RELEVANCE);
+        assertThat(td.totalHits.value, equalTo(count));        
+    }
+    
+    private void expectPrefixMatch(IndexSearcher searcher, String term,long count) throws IOException {
+        Query q = wildcardFieldType.fieldType().prefixQuery(term, null, MOCK_QSC);
+        TopDocs td = searcher.search(q, 10, Sort.RELEVANCE);
+        assertThat(td.totalHits.value, equalTo(count));        
+    }    
 
 
     public void testSearchResultsVersusKeywordField() throws IOException {