diff --git a/src/java/org/apache/poi/util/LittleEndianByteArrayInputStream.java b/src/java/org/apache/poi/util/LittleEndianByteArrayInputStream.java index ff88e7164a..fcb44f653e 100644 --- a/src/java/org/apache/poi/util/LittleEndianByteArrayInputStream.java +++ b/src/java/org/apache/poi/util/LittleEndianByteArrayInputStream.java @@ -37,7 +37,8 @@ public class LittleEndianByteArrayInputStream extends ByteArrayInputStream imple protected void checkPosition(int i) { if (i > count - pos) { - throw new RuntimeException("Buffer overrun"); + throw new RuntimeException("Buffer overrun, having " + count + " bytes in the stream and position is at " + pos + + ", but trying to increment position by " + i); } } diff --git a/src/testcases/org/apache/poi/util/TestLittleEndianStreams.java b/src/testcases/org/apache/poi/util/TestLittleEndianStreams.java index c05e365a92..1b327669ae 100644 --- a/src/testcases/org/apache/poi/util/TestLittleEndianStreams.java +++ b/src/testcases/org/apache/poi/util/TestLittleEndianStreams.java @@ -81,4 +81,20 @@ public final class TestLittleEndianStreams extends TestCase { assertEquals(0x33, lei.readUByte()); assertEquals(0, lei.available()); } + + public void testBufferOverrun() { + byte[] srcBuf = HexRead.readFromString("99 88 77"); + LittleEndianInput lei = new LittleEndianByteArrayInputStream(srcBuf); + + // do initial read to increment the read index beyond zero + assertEquals(0x8899, lei.readUShort()); + + // only one byte left, so this should fail + try { + lei.readFully(new byte[4]); + fail("Should catch exception here"); + } catch (RuntimeException e) { + assertTrue(e.getMessage().contains("Buffer overrun")); + } + } }