gistfile1.txt

<?php    
                                                                       
use PHPUnit_Framework_TestCase as BaseTestCase;                                 
                                                                                
class TestFixer extends BaseTestCase                                            
{                                                                               
    public function fix(&$target, $source, $keep = false) {                     
        if (!$source) {                                                         
            return;                                                             
        }                                                                       
        $keys = array();                                                        
                                                                                
        $source = preg_replace_callback(                                        
            '/                                                                  
            # Match at start of string or &                                     
            (?:^|(?<=&))                                                        
            # Exclude cases where the period is in brackets, e.g. foo[bar.blarg]
            [^=&\[]*                                                            
            # Affected cases: periods and spaces                                
            (?:\.|%20)                                                          
            # Keep matching until assignment, next variable, end of string or   
            # start of an array                                                 
            [^=&\[]*                                                            
            /x',                                                                
            function ($key) use (&$keys) {                                      
                $keys[] = $key = base64_encode(urldecode($key[0]));             
                return urlencode($key);                                         
            },                                                                  
        $source                                                                 
        );                                                                      
                                                                                
        if (!$keep) {                                                           
            $target = array();                                                  
        }                                                                       
                                                                                
        parse_str($source, $data);                                              
        foreach ($data as $key => $val) {                                       
            // Only unprocess encoded keys                                      
            if (!in_array($key, $keys)) {                                       
                $target[$key] = $val;                                           
                continue;                                                       
            }                                                                   
                                                                                
            $key = base64_decode($key);                                         
            $target[$key] = $val;                                               
                                                                                
            if ($keep) {                                                        
                // Keep a copy in the underscore key version                    
                $key = preg_replace('/(\.| )/', '_', $key);                     
                $target[$key] = $val;                                           
            }                                                                   
        }                                                                       
    }                                                                           
                                                                                
    public function dataForTestFix()                                            
    {                                                                           
        return array(                                                           
            // Simple cases                                                     
            ['foo=bar', ['foo' => 'bar']],                                      
            ['foo=foo.bar', ['foo' => 'foo.bar']],                              
            ['foo=foo.bar[]', ['foo' => 'foo.bar[]']],                          
            ['foo[]=bar', ['foo' => ['bar']]],                                  
            ['foo.bar', ['foo.bar' => '']],                                     
            ['foo.bar[]', ['foo.bar' => ['']]],                                 
            ['foo%20bar', ['foo bar' => '']],                                   
            ['foo%20bar[]', ['foo bar' => ['']]],                               
            ['foo[foo.bar]=bar', ['foo' => ['foo.bar' => 'bar']]],              
            ['foo[foo%20bar]=bar', ['foo' => ['foo bar' => 'bar']]],            
                                                                                
            // Simple cases with keeping                                        
            ['foo=bar', ['foo' => 'bar'], true],                                
            ['foo=foo.bar', ['foo' => 'foo.bar'], true],                        
            ['foo=foo.bar[]', ['foo' => 'foo.bar[]'], true],                    
            ['foo[]=bar', ['foo' => ['bar']], true],                            
            ['foo.bar', ['foo_bar' => '', 'foo.bar' => ''], true],              
            ['foo.bar[]', ['foo_bar' => [''], 'foo.bar' => ['']], true],        
            ['foo%20bar', ['foo_bar' => '', 'foo bar' => ''], true],            
            ['foo%20bar[]', ['foo_bar' => [''], 'foo bar' => ['']], true],      
            ['foo[foo.bar]=bar', ['foo' => ['foo.bar' => 'bar']], true],        
            ['foo[foo%20bar]=bar', ['foo' => ['foo bar' => 'bar']], true],      
                                                                                
            // Duplicates if cast to "_"                                        
            ['foo.bar=blarg1&foo_bar=blarg2&foo%20bar=blarg3', ['foo.bar' => 'blarg1', 'foo_bar' => 'blarg2', 'foo bar' => 'blarg3']],
            ['foo.bar=blarg1&foo_bar=blarg2&foo%20bar=blarg3', ['foo_bar' => 'blarg3', 'foo.bar' => 'blarg1', 'foo bar' => 'blarg3'], true],
                                                                                
            array(                                                              
                'foo%20bar=blarg&foo[bar][blarg.bar]=bar&foo.bar=blarg&foobar.blarg[]=bar&blarg.foo&blargfoo.bar[asdf]=w00t&normal=normal',
                array(                                                          
                    'foo bar' => 'blarg',                                       
                    'foo' => array(                                             
                        'bar' => array(                                         
                            'blarg.bar' => 'bar',                               
                        ),                                                      
                    ),                                                          
                    'foo.bar' => 'blarg',                                       
                    'foobar.blarg' => array('bar'),                             
                    'blarg.foo' => null,                                        
                    'blargfoo.bar' => array(                                    
                        'asdf' => 'w00t',                                       
                    ),                                                          
                    'normal' => 'normal',                                       
                )                                                               
            ),                                                                  
        );                                                                      
    }                                                                           
                                                                                
    /**                                                                         
     * @dataProvider dataForTestFix                                             
     */                                                                         
    public function testFixWorks($string, $target, $keep = false)               
    {                                                                           
        parse_str($string, $source);                                            
        $this->fix($source, $string, $keep);                                    
        $this->assertEquals($source, $target);                                  
    }                                                                           
}                                                                               

http://stackoverflow.com/questions/68651/get-php-to-stop-replacing-characters-in-get-or-post-arrays

Thanks for sharing, implemented it in a project of mine ;)