#23222 [Opn->Bgs]: anomaly re: zlib.output_compression and header("Location:...

ID: 23222 Updated by: edink@php.net Reported By: nospam at 1111-internet dot com -Status: Open +Status: Bogus Bug Type: Output Control Operating System: FreeBSD 4.8 PHP Version: 4.3.1 New Comment: This is not a bug, but a feature of PHP's output buffering. Whenever you have any sort of output buffering enabled header() function will work until the buffers are flushed to the output. Previous Comments: ------------------------------------------------------------------------ [2003-04-15 03:13:47] nospam at 1111-internet dot com Consider the following code: <?php echo str_repeat("x", 4095); header("Location: /somewhere_else.php"); exit; ?> If zlib.output_compression is off, this will cause 4095 "x"s to display, properly followed by an error on the header line. If zlib.output_compression is on, however, the echo line will execute - but nothing is output immediately because it fails to fill the compression buffer - so the header line goes ahead and executes and redirects successfully, completely spurning the output. Granted, nobody would use this particular example in a real world application - I just set it up to illustrate the problem. I have run into real situations, though, where I'm doing diagnostics or inadvertently cause an error on code lines that logically precede a header("Location:... call. This problem prevents my diagnistic or error messages from showing up. Consider: <?php // set up mysql connection and mysql_query("insert into mytable (myfield) values (". $_GET["myvalue"]. ")"); // no problem if $_GET["myvalue"] is a number, // but if it's a non-numeric string like "abc" that line will generate an error message // which I would like to see so I can fix the problem... // but the error message doesn't fill the compression buffer // so the following redirect happens and usurps the error message header("Location: /somewhere_else.php"); exit; // so I go on as though there was never a problem // until I look at my still-empty database table some time later... ?> ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=23222&edit=1