0002271: thinko in base_convert: doesn't always work for large bases

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Category

Severity

Reproducibility

Date Submitted

Last Update

0002271

[Quercus]

minor

always

12-21-07 07:25

02-05-08 12:39

Reporter

jang

View Status

public

Assigned To

nam

Priority

normal

Resolution

fixed

Status

closed

Product Version

3.1.3

Summary

0002271: thinko in base_convert: doesn't always work for large bases

Description

There's a bug in MathModule#base_convert - two, actually. The first is the conversion of the input value to a long result:

     if ('0' <= ch && ch <= '9')
        value = ch - '0';
      else if ('a' <= ch && ch <= 'z')
        value = ch - 'a' + 10;
      else if ('A' <= ch && ch <= 'Z')
        value = ch - 'a' + 10;

Pretty sure that last line should be, er,

        value = ch - 'A' + 26;

(which 'a' - 10 doesn't evaluate to).

On output, something similar:

      if (d < 10)
        sb.append((char) (d + '0'));
      else
        sb.append((char) (d - 10 + 'a'));

is also erroneous. Additional information is a sample piece of code that demonstrates this: it'll spew out nonprintable characters occasionally.

Caught this whilst hacking on Elgg to make it run under quercus; as it is, the piece of Elgg code that does this is pretty broken too :-/ but figured you'd probably want the fix anyway.

Cheers,
jan

Additional Information

<?php
        $s = md5(time() . "123");
        echo $s;
        echo "\n";
        echo base_convert($s, 16, 36);
?>

Attached Files

Relationships

Notes
(0002721) nam 02-05-08 12:39	php/1328 php/1329

Issue History
Date Modified	Username	Field	Change
12-21-07 07:25	jang	New Issue
12-28-07 09:23	jang	Issue Monitored: jang
02-05-08 11:38	nam	Status	new => assigned
02-05-08 11:38	nam	Assigned To	=> nam
02-05-08 12:39	nam	Status	assigned => closed
02-05-08 12:39	nam	Note Added: 0002721
02-05-08 12:39	nam	Resolution	open => fixed
02-05-08 12:39	nam	Fixed in Version	=> 3.1.5

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