[jira] Updated: (HARMONY-166) method read() in InputStreamReader failed to read one character

["Vladimir Strigun (JIRA)" <ji...@apache.org>]

     [ http://issues.apache.org/jira/browse/HARMONY-166?page=all ]

Vladimir Strigun updated HARMONY-166:
-------------------------------------

    Attachment: InputStreamReader.java.patch

Mikhail,

please review my patch.  Now method read() is not modified. I just add decoding operations to fillBuf() method. 
Method available() is still used to determine endOfInput parameter. According to specification the method should be overridden by subclasses.

> method read() in InputStreamReader failed to read one character
> ---------------------------------------------------------------
>
>          Key: HARMONY-166
>          URL: http://issues.apache.org/jira/browse/HARMONY-166
>      Project: Harmony
>         Type: Bug

>   Components: Classlib
>     Reporter: Vladimir Strigun
>  Attachments: InputStreamReader.java.patch, InputStreamReader.patch.txt, InputStreamReaderTest.java
>
> I've started to play with harmony-57 contribution and found bug in InputStreamReader class. Method read() should read a single character from input stream but it works incorrectly for 2 bytes-per-char charsets. Example below shows that it failed to read one character in UTF-16 charset. Sorry for so ugly test, it's just a part of InputStreamReaderTest from Harmony-57 contribution. 
> import java.io.*;
> import junit.framework.TestCase;
> public class InputStreamReaderTest extends TestCase {
> 	public static void main(String[] args) {
> 		junit.textui.TestRunner.run(InputStreamReaderTest.class);
> 	}
> 	public void test_ISR_read() throws Exception {
> 		InputStream in;
> 		InputStreamReader reader;
> 		try {
> 			in = new LimitedByteArrayInputStream(0);
> 			reader = new InputStreamReader(in, "UTF-16BE");
> 			int xx = reader.read();
> 			assertTrue("Incorrect byte UTF-16BE", xx == '\u6172');
> 		} catch (UnsupportedEncodingException e) {
> 			// Can't test without the converter
> 			System.out.println(e);
> 		} catch (IOException e) {
> 			e.printStackTrace();
> 			fail("UTF-16BE unexpected 1: " + e);
> 		}
> 		try {
> 			in = new LimitedByteArrayInputStream(0);
> 			reader = new InputStreamReader(in, "UTF-16LE");
> 			int xx = reader.read();
> 			assertTrue("Incorrect byte UTF-16BE", xx == '\u7261');
> 		} catch (UnsupportedEncodingException e) {
> 			// Can't test without the converter
> 		} catch (IOException e) {
> 			fail("UTF-16BE unexpected 2: " + e);
> 		}
> 		try {
> 			in = new LimitedByteArrayInputStream(1);
> 			reader = new InputStreamReader(in, "UTF-16");
> 			assertTrue("Incorrect byte UTF-16BE", reader.read() == '\u7261');
> 		} catch (UnsupportedEncodingException e) {
> 			// Can't test without the converter
> 		} catch (IOException e) {
> 			fail("UTF-16BE unexpected 3: " + e);
> 		}
> 		try {
> 			in = new LimitedByteArrayInputStream(2);
> 			reader = new InputStreamReader(in, "ISO2022JP");
> 			int ch = reader.read();
> 			assertTrue("Incorrect byte ISO2022JP 1: " + ch, ch == '\u4e5d');
> 			ch = reader.read();
> 			assertTrue("Incorrect byte ISO2022JP 2: " + ch, ch == '\u7b2c');
> 		} catch (UnsupportedEncodingException e) {
> 			// Can't test without the converter
> 			System.out.println(e);
> 		} catch (IOException e) {
> 			fail("ISO2022JP unexpected: " + e);
> 		}
> 	}
> 	static class LimitedByteArrayInputStream extends ByteArrayInputStream {
> 		// A ByteArrayInputStream that only returns a single byte per read
> 		byte[] bytes;
> 		int count;
> 		public LimitedByteArrayInputStream(int type) {
> 			super(new byte[0]);
> 			switch (type) {
> 			case 0:
> 				bytes = new byte[] { 0x61, 0x72 };
> 				break;
> 			case 1:
> 				bytes = new byte[] { (byte) 0xff, (byte) 0xfe, 0x61, 0x72 };
> 				break;
> 			case 2:
> 				bytes = new byte[] { '\u001b', '$', 'B', '6', 'e', 'B', 'h',
> 						'\u001b', '(', 'B' };
> 				break;
> 			}
> 			count = bytes.length;
> 		}
> 		public int read() {
> 			if (count == 0)
> 				return -1;
> 			count--;
> 			return bytes[bytes.length - count];
> 		}
> 		public int read(byte[] buffer, int offset, int length) {
> 			if (count == 0)
> 				return -1;
> 			if (length == 0)
> 				return 0;
> 			buffer[offset] = bytes[bytes.length - count];
> 			count--;
> 			return 1;
> 		}
> 		public int available() {
> 			return count;
> 		}
> 	}
> }

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