GB18030 false positive with WINDOWS-1252 data set

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What steps will reproduce the problem?
1. Pass UniversalDetector a byte buffer for WINDOWS-1252 containing a series of 
degree symbols and character / numbers
 e.g. {91, -80, 52, -80, 48, -80, 84, -80, 67, -80, 67, -80, 48, -80, 67, -80, 84}
2. Call UniversalDetector#getDetectedCharset(), it should be WINDOWS-1252, but 
instead returns GB18030.

See attached unit test for minimal reproduction test case.

What is the expected output? What do you see instead?
Expected output from UniversalDetector#getDetectedCharset() is "WINDOWS-1252," 
but instead is "GB18030."

What version of the product are you using? On what operating system?
 I'm using version 1.0.3 on 64-bit Ubuntu 11.4 (Natty) with default kernel 2.6.38-10-generic.  The JDK I'm currently running is 1.6.0_23-x64.

Original issue reported on code.google.com by icw...@gmail.com on 13 Jul 2011 at 4:34

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Unit test attached

Original comment by icw...@gmail.com on 13 Jul 2011 at 4:41

Attachments:

• GB18030SMFalsePositiveTest.java

[GoogleCodeExporter]

Experienced the same issue. Changing the buffersize for reading the inputstream 
from 4096 to 128 solved the problem. The error occurred with buffer sizes of 
253 and above.

Original comment by eman0...@gmail.com on 28 Feb 2012 at 9:39

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[deleted comment]

[GoogleCodeExporter]

Changing the buffersize did not solve the issue on real files. 

The workaround I am currently using is to detect if one or more degree 
characters (°) are present in the byte stream(buf[i] == (byte) 0xB0). If true 
and if the detector returns "GB18030", I use "WINDOWS-1252" instead.
This gives good results (as long as you do not have to detect GB18030 encoded 
files)

Original comment by juliende...@gmail.com on 29 Jan 2015 at 10:20