[bug-66365] update XSSFExcelExtractor to better handle formula cells with cached results of string type

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1905572 13f79535-47bb-0310-9956-ffa450edef68

poi-ooxml/src/main/java/org/apache/poi/xssf/extractor/XSSFExcelExtractor.java

@@ -224,6 +224,10 @@ public class XSSFExcelExtractor
         CellType type = cell.getCellType();
         if (type == CellType.FORMULA) {
             type = cell.getCachedFormulaResultType();
+            if (type == CellType.STRING) {
+                handleStringCell(text, cell);
+                return;
+            }
         }
 
         if (type == CellType.NUMERIC) {