Merge pull request #1316 from antony-liu/poi/v3.16-patch3

Some patches ported from poi

main/HSSF/Extractor/OldExcelExtractor.cs

@@ -39,6 +39,7 @@ namespace NPOI.HSSF.Extractor
      */
     public class OldExcelExtractor
     {
+        private const int FILE_PASS_RECORD_SID = 0x2f;
         private RecordInputStream ris;
 
         // sometimes we hold the stream here and thus need to ensure it is closed at some point
@@ -247,6 +248,9 @@ public String Text
 
                     switch (sid)
                     {
+                        case FILE_PASS_RECORD_SID:
+                            throw new EncryptedDocumentException("Encryption not supported for Old Excel files");
+
                         // Biff 5+ only, no sheet names in older formats
                         case OldSheetRecord.sid:
                             OldSheetRecord shr = new OldSheetRecord(ris);

main/Util/StringUtil.cs

@@ -854,5 +854,28 @@ public static String Join(String separator, params object[] array)
         {
             return Join(array, separator);
         }
+
+        /**
+        * Count number of occurrences of needle in haystack
+        * Has same signature as org.apache.commons.lang3.StringUtils#countMatches
+        *
+        * @param haystack  the CharSequence to check, may be null
+        * @param needle    the character to count the quantity of 
+        * @return the number of occurrences, 0 if the CharSequence is null
+        */
+        public static int CountMatches(string haystack, char needle)
+        {
+            if (haystack == null) return 0;
+            int count = 0;
+            int length = haystack.Length;
+            for (int i = 0; i < length; i++)
+            {
+                if (haystack[i] == needle)
+                {
+                    count++;
+                }
+            }
+            return count;
+        }
     }
 }