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

Platform

Status

closed

Projection

none

OS Version

ETA

none

Fixed in Version

3.1.5

Product Version

3.1.3

Product Build

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

Steps To Reproduce

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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