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ID: Category: Severity: Reproducibility: Date Submitted: Last Update:
2125 minor always 10-27-07 01:27 08-11-08 15:39
Reporter: koreth Platform:  
Assigned To: ferg OS:  
Priority: normal OS Version:  
Status: closed Product Version: 3.1.3  
Product Build: Resolution: fixed  
Projection: none      
ETA: none Fixed in Version: 3.2.1  
Summary: 0002125: Integer from MySQL query disappears on array append operation
Description: I construct an array of results from a MySQL query:

$raw_thread_rows = array();
while ($row = mysql_fetch_assoc($ret)) {
  $raw_thread_rows[]= $row;
}

Then, later on, I iterate over that data trying to generate an array of values from one of the columns, and it fails. I add debug information:

$thread_ids = array();
foreach ($raw_thread_rows as $r) {
  error_log("Raw thread row = " . print_r($r, true));
  $thread_ids[] = $r['thread_id'];
  error_log("Thread ID array = " . print_r($thread_ids, true));
}

And here's the output I get (or at least the first few iterations of it):

Raw thread row = Array
(
    [user] => 500018751
    [thread_id] => 5963202122
    [last_update] => 1193435269
    [num_unread] => 0
)

Thread ID array = Array
(
    [0] =>
)

Raw thread row = Array
(
    [user] => 500018751
    [thread_id] => 5703323014
    [last_update] => 1193186680
    [num_unread] => 0
)

Thread ID array = Array
(
    [0] =>
    [1] =>
)

Raw thread row = Array
(
    [user] => 500018751
    [thread_id] => 5849902182
    [last_update] => 1192735312
    [num_unread] => 0
)

Thread ID array = Array
(
    [0] =>
    [1] =>
    [2] =>
)
Steps To Reproduce:
Additional Information:
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Attached Files:

Notes
(0002399)
koreth   
10-27-07 13:40   
I have narrowed this down a bit more and I believe I mischaracterized it above. This only happens after objects from the MySQL query are stored into and then retrieved from our cache, meaning they pass through our custom object serializer.

It is actually a problem in StringBuilderValue.equals(). If you pass that function a BinaryBuilderValue representing the same string, it returns false. My serializer implementation doesn't differentiate between binary and string values because our PHP code expects to be able to serialize either binary or text data; in vanilla PHP the two are not distinct from one another and I didn't want any Unicode transformations happening under the covers to confuse things.

I think it should probably be the case that a StringBuilderValue and a BinaryBuilderValue that evaluate to the same value on the PHP side should test as equal. But in the meantime I will change my serializer to scan the data it's unserializing and produce a StringBuilderValue if there aren't any non-ASCII bytes in the value.
(0002400)
koreth   
10-27-07 13:41   
A little more detail, actually: what's happening is that ArrayValueImpl.get() is being passed a StringBuilderValue by the above code. It computes the correct hash value, but skips over the array entry it should be matching because the key happens to be a BinaryBuilderValue.
(0002403)
ferg   
10-29-07 13:22   
Actually, it's more complicated than that.

StringBuilderValue is the PHP5 string (or unicode.semantics='false')

BinaryBuilderValue is a PHP6 string with unicode.semantics='true'. It is not a PHP5 object at all.

In PHP6 with unicode.semantics=true, "a" === b"a" evaluates to false, and the following generates two distinct entries:

  $a = array();
  $a["a"] = 3;
  $a[b"a"] = 4;
  var_dump($a);

  array(2) {
    [u"a"]=>
    int(3)
    ["a"]=>
    int(4)
  }
(0002404)
koreth   
10-29-07 13:26   
In that case, maybe this is a documentation issue; the difference in semantics between binary and string values isn't described anywhere (that I saw) in the documentation describing how to interface between PHP and Java.