[bug-69628] make IOUtils more tolerant of len < 0

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1924601 13f79535-47bb-0310-9956-ffa450edef68

Author: pjfanning

poi/src/main/java/org/apache/poi/util/IOUtils.java

@@ -248,15 +248,12 @@ public static byte[] toByteArrayWithMaxLength(InputStream stream, final int maxL
 
     private static byte[] toByteArray(InputStream stream, final int length, final int maxLength,
                                       final boolean checkEOFException, final boolean isLengthKnown) throws IOException {
-        if (length < 0 || maxLength < 0) {
-            throw new RecordFormatException("Can't allocate an array of length < 0");
-        }
         final int derivedMaxLength = Math.max(maxLength, BYTE_ARRAY_MAX_OVERRIDE);
         if ((length != Integer.MAX_VALUE) || (derivedMaxLength != Integer.MAX_VALUE)) {
             checkLength(length, derivedMaxLength);
         }
 
-        final int derivedLen = isLengthKnown ? Math.min(length, derivedMaxLength) : derivedMaxLength;
+        final int derivedLen = isLengthKnown && length >= 0 ? Math.min(length, derivedMaxLength) : derivedMaxLength;
         final int byteArrayInitLen = calculateByteArrayInitLength(isLengthKnown, length, derivedMaxLength);
         final int internalBufferLen = DEFAULT_BUFFER_SIZE;
         try (UnsynchronizedByteArrayOutputStream baos = UnsynchronizedByteArrayOutputStream.builder().setBufferSize(byteArrayInitLen).get()) {
@@ -275,7 +272,7 @@ private static byte[] toByteArray(InputStream stream, final int length, final in
                 throwRecordTruncationException(derivedMaxLength);
             }
 
-            if (checkEOFException && derivedLen != Integer.MAX_VALUE && totalBytes < derivedLen) {
+            if (checkEOFException && length >= 0 && derivedLen != Integer.MAX_VALUE && totalBytes < derivedLen) {
                 throw new EOFException("unexpected EOF - expected len: " + derivedLen + " - actual len: " + totalBytes);
             }
 

poi/src/test/java/org/apache/poi/util/TestIOUtils.java

@@ -110,8 +110,25 @@ void testToByteArrayMaxLengthTooSmall() {
     }
 
     @Test
-    void testToByteArrayNegativeLength() {
-        assertThrows(RecordFormatException.class, () -> IOUtils.toByteArray(data123(), -1));
+    void testToByteArrayNegativeLength() throws IOException {
+        final byte[] array = new byte[]{1, 2, 3, 4, 5, 6, 7};
+        IOUtils.setByteArrayMaxOverride(30 * 1024 * 1024);
+        try (ByteArrayInputStream is = new ByteArrayInputStream(array)) {
+            assertArrayEquals(array, IOUtils.toByteArray(is, -1, 100));
+        } finally {
+            IOUtils.setByteArrayMaxOverride(-1);
+        }
+    }
+
+    @Test
+    void testToByteArrayNegativeLength2() throws IOException {
+        final byte[] array = new byte[]{1, 2, 3, 4, 5, 6, 7};
+        IOUtils.setByteArrayMaxOverride(30 * 1024 * 1024);
+        try (ByteArrayInputStream is = new ByteArrayInputStream(array)) {
+            assertArrayEquals(array, IOUtils.toByteArray(is, -1));
+        } finally {
+            IOUtils.setByteArrayMaxOverride(-1);
+        }
     }
 
     @Test