[github-187] Add length validation for Excel DataValidations that are list literals. Thanks to Leo Webb. This closes #187

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1880727 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFDataValidationConstraint.java

@@ -31,10 +31,12 @@ public class XSSFDataValidationConstraint implements DataValidationConstraint {
     /**
      * Excel validation constraints with static lists are delimited with optional whitespace and the Windows List Separator,
      * which is typically comma, but can be changed by users. POI will just assume comma.
+	 * In addition, Excel validation with static lists has a maximum size of 255 characters, including separators and excluding quotes.
      */
     private static final String LIST_SEPARATOR = ",";
     private static final Pattern LIST_SPLIT_REGEX = Pattern.compile("\\s*" + LIST_SEPARATOR + "\\s*");
     private static final String QUOTE = "\"";
+	private static final int MAX_EXPLICIT_LIST_LENGTH = 257;
 
 	private String formula1;
 	private String formula2;
@@ -204,6 +206,9 @@ public class XSSFDataValidationConstraint implements DataValidationConstraint {
 			if (isFormulaEmpty(formula1)) {
 				throw new IllegalArgumentException("A valid formula or a list of values must be specified for list validation.");
 			}
+			if(formula1.length() > MAX_EXPLICIT_LIST_LENGTH) {
+				throw new IllegalArgumentException("A valid formula or a list of values must be less than or equal to 255 characters (including separators).");
+			}
 		} else  {
 			if( isFormulaEmpty(formula1) ) {
 				throw new IllegalArgumentException("Formula is not specified. Formula is required for all validation types except explicit list validation.");

src/ooxml/testcases/org/apache/poi/xssf/usermodel/TestXSSFDataValidationConstraint.java

@@ -18,11 +18,18 @@ package org.apache.poi.xssf.usermodel;
 
 import static org.junit.Assert.*;
 
+import org.apache.poi.ss.formula.DataValidationEvaluator;
 import org.apache.poi.ss.usermodel.DataValidationConstraint;
 import org.apache.poi.ss.usermodel.DataValidationConstraint.ValidationType;
+import org.apache.poi.xssf.XSSFTestDataSamples;
 import org.apache.poi.ss.usermodel.DataValidationConstraint.OperatorType;
+import org.apache.poi.ss.util.CellReference;
 import org.junit.Test;
 
+import java.util.Collections;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
 public class TestXSSFDataValidationConstraint {
     static final int listType = ValidationType.LIST;
     static final int ignoredType = OperatorType.IGNORED;
@@ -51,6 +58,20 @@ public class TestXSSFDataValidationConstraint {
         assertEquals(literal.replace(" ", ""), constraint.getFormula1());
     }
 
+    @Test
+    public void listLiteralsGreaterThan255CharactersThrows() {
+        String[] literal = IntStream.range(0, 129).mapToObj(i -> "a").toArray(String[]::new);
+        assertThrows(IllegalArgumentException.class, () -> new XSSFDataValidationConstraint(literal));
+    }
+    
+    @Test
+    public void dataValidationListLiteralTooLongFromFile() {
+        XSSFWorkbook wb = XSSFTestDataSamples.openSampleWorkbook("DataValidationListTooLong.xlsx");
+        XSSFFormulaEvaluator fEval = wb.getCreationHelper().createFormulaEvaluator();
+        DataValidationEvaluator dvEval = new DataValidationEvaluator(wb, fEval);
+        assertThrows(IllegalArgumentException.class, () -> dvEval.getValidationValuesForCell(new CellReference("Sheet0!A1")));
+    }
+
     @Test
     public void rangeReference() {
         // (unnamed range) reference list