Merge pull request #434 from sahvx655-wq/isbn-convert-validate

Reject invalid ISBN-10 in convertToISBN13

Author: garydgregory

src/main/java/org/apache/commons/validator/routines/ISBNValidator.java

@@ -179,6 +179,9 @@ public String convertToISBN13(final String isbn10) {
         if (input.length() != ISBN_10_LEN) {
             throw new IllegalArgumentException("Invalid length " + input.length() + " for '" + input + "'");
         }
+        if (!isbn10Validator.isValid(input)) {
+            return null;
+        }
 
         // Calculate the new ISBN-13 code (drop the original checkdigit)
         String isbn13 = "978" + input.substring(0, ISBN_10_LEN - 1);

src/test/java/org/apache/commons/validator/routines/ISBNValidatorTest.java

@@ -96,10 +96,22 @@ void testConversionErrors() {
         final String input3 = "";
         assertThrows(IllegalArgumentException.class, () -> validator.convertToISBN13(input3), "Expected IllegalArgumentException for '" + input3 + "'");
 
-        final String input4 = "X234567890";
+        final String input4 = "1234567890X";
         assertThrows(IllegalArgumentException.class, () -> validator.convertToISBN13(input4), "Expected IllegalArgumentException for '" + input4 + "'");
     }
 
+    /**
+     * Test method for {@link org.apache.commons.validator.routines.ISBNValidator#convertToISBN13(java.lang.String)}.
+     */
+    @Test
+    void testConvertToISBN13Invalid() {
+        final ISBNValidator validator = ISBNValidator.getInstance();
+        // Correct length, but not a valid ISBN-10.
+        assertNull(validator.convertToISBN13("1234567890"), "wrong check digit");
+        assertNull(validator.convertToISBN13("020163385Y"), "invalid check character");
+        assertNull(validator.convertToISBN13("X234567890"), "non-digit body");
+    }
+
     /**
      * Test Invalid ISBN-10 codes
      */