6990617: Regular expression doesn't match if unicode character next to a digit.

[Stephen Flores]

Thanks Gary,

I have added the bug number to the tag and updated the webrev.

Steve.

On 12/12/2011 10:05 AM, Gary Adams wrote:
> I think you want to add 6990617 to the @bug tag in RegExTest.
>
> On 12/10/11 01:05 AM, Stephen Flores wrote:
>> Please review the following webrev (includes new test to demonstrate
>> the bug):
>>
>> http://cr.openjdk.java.net/~sflores/6990617/
>>
>> for bug: 6990617 Regular expression doesn't match if unicode character
>> next to a digit.
>>
>> A DESCRIPTION OF THE PROBLEM :
>>
>> Unicode characters are represented as \\+number.
>> For instance, one could write:
>> Pattern p = Pattern.compile("\\011some text\\012");
>> Matcher m = p.matcher("\tsome text\n");
>> System.out.println(m.find()); // yields "true"
>>
>> However, if we want to match a string with a digit next to
>> the unicode character, it doesn't match (whether we "quote"
>> the regular expression or not). Note the "1" next to the tab
>> character (unicode 011).
>> Pattern p = Pattern.compile("\\011\\Q1some text\\E\\012");
>> Matcher m = p.matcher("\t1some text\n");
>> System.out.println(m.find()); // yields "false"
>>
>> This happens because Pattern accepts either \\0011 or \\011 for
>> the same character. From the javadoc:
>>
>> \0nn The character with octal value 0nn (0 <= n <= 7)
>> \0mnn The character with octal value 0mnn (0 <= m <= 3, 0 <= n <= 7)
>>
>> Evaluation:
>>
>> Pattern.RemoveQEQuoting() does NOT handle this situation correctly.
>> The existing implementation now simply copies all ASCII.isAlnum()
>> characters when handing a quote.
>>
>> Description of fix:
>>
>> In the method Pattern.RemoveQEQuoting any ASCII digit at the
>> beginning of a quote will now be prefixed by "\x3" (not just \
>> because this would be a backref). 0x30 is the ASCII code for '0'.
>>
>> Thanks,
>>
>> Steve.
>