Avoid NullPointerException in IOCase.checkRegionMatches(String, int,

String) on null input

Author: garydgregory

src/changes/changes.xml

@@ -73,6 +73,7 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Avoid NullPointerException in HiddenFileFilter.accept(File) on null input.</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Avoid NullPointerException in HiddenFileFilter.accept(Path, BasicFileAttributes) on null input.</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Avoid NullPointerException in IOCase.checkIndexOf(String, int, String) on null input.</action>
+      <action dev="ggregory" type="fix"                due-to="Gary Gregory">Avoid NullPointerException in IOCase.checkRegionMatches(String, int, String) on null input.</action>
       <!-- Add -->
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Add and use PathUtils.getFileName(Path, Function&lt;Path, R&gt;).</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Add and use PathUtils.getFileNameString().</action>

src/main/java/org/apache/commons/io/IOCase.java

@@ -208,14 +208,13 @@ public int checkIndexOf(final String str, final int strStartIndex, final String
      * but takes case-sensitivity into account.
      * </p>
      *
-     * @param str  the string to check, not null.
+     * @param str  the string to check.
      * @param strStartIndex  the index to start at in str.
-     * @param search  the start to search for, not null.
+     * @param search  the start to search for,.
      * @return true if equal using the case rules.
-     * @throws NullPointerException if either string is null.
      */
     public boolean checkRegionMatches(final String str, final int strStartIndex, final String search) {
-        return str.regionMatches(!sensitive, strStartIndex, search, 0, search.length());
+        return str != null && search != null && str.regionMatches(!sensitive, strStartIndex, search, 0, search.length());
     }
 
     /**

src/test/java/org/apache/commons/io/IOCaseTest.java

@@ -241,12 +241,12 @@ public void test_checkRegionMatches_functionality() {
         assertFalse(IOCase.SENSITIVE.checkRegionMatches("", 1, "ABC"));
         assertFalse(IOCase.SENSITIVE.checkRegionMatches("", 1, ""));
 
-        assertThrows(NullPointerException.class, () -> IOCase.SENSITIVE.checkRegionMatches("ABC", 0, null));
-        assertThrows(NullPointerException.class, () -> IOCase.SENSITIVE.checkRegionMatches(null, 0, "ABC"));
-        assertThrows(NullPointerException.class, () -> IOCase.SENSITIVE.checkRegionMatches(null, 0, null));
-        assertThrows(NullPointerException.class, () -> IOCase.SENSITIVE.checkRegionMatches("ABC", 1, null));
-        assertThrows(NullPointerException.class, () -> IOCase.SENSITIVE.checkRegionMatches(null, 1, "ABC"));
-        assertThrows(NullPointerException.class, () -> IOCase.SENSITIVE.checkRegionMatches(null, 1, null));
+        assertFalse(IOCase.SENSITIVE.checkRegionMatches("ABC", 0, null));
+        assertFalse(IOCase.SENSITIVE.checkRegionMatches(null, 0, "ABC"));
+        assertFalse(IOCase.SENSITIVE.checkRegionMatches(null, 0, null));
+        assertFalse(IOCase.SENSITIVE.checkRegionMatches("ABC", 1, null));
+        assertFalse(IOCase.SENSITIVE.checkRegionMatches(null, 1, "ABC"));
+        assertFalse(IOCase.SENSITIVE.checkRegionMatches(null, 1, null));
     }
 
     @Test