Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!news.swapon.de!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Arno Welzel Newsgroups: comp.lang.php Subject: Re: totally WEIRD bug? Firefox caching? Date: Thu, 20 Mar 2014 15:53:48 +0100 Lines: 63 Message-ID: <532B00FC.8@arnowelzel.de> References: <532AB145.8080504@arnowelzel.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: individual.net JMwjyA7s5DSEdgmEy0chlAOoo2mFebAGD6AJWjG7LerweZ4FMX Cancel-Lock: sha1:+5C39+/r55a/leFNdn5JICpLgrA= User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 In-Reply-To: Xref: csiph.com comp.lang.php:13250 Am 20.03.2014 12:26, schrieb The Natural Philosopher: > On 20/03/14 09:13, Arno Welzel wrote: >> Am 19.03.2014 18:25, schrieb The Natural Philosopher: >> >>> I have TWO IDENTICAL PHP FILES. >>> >>> They are supposed to display an image got from a database. >>> >>> One does. The other does not. >>> >>> It persistently tells me the image is corrupted. >>> >>> I have even copied one file that works directly over the other. It still >>> doesn't work. [...] > What is happning - and oddly running it against a test version of IE6 in > my XP VM showed it up, was that it was outputting a '404 file not found' > text BEFORE outputting perfectly valid PNG. > > Why this is happening is a bug somewhere else completely. > > IE 6 simply showed the text and the binary gobbledygook which was the > clue I needed. Yes, because IE 6 assumes the user may not understand a server generated error message and shows its own message as long as the reponse is below a certain size limit (AFAIR less than 4000 bytes, but i may not remember correctly). This is even more annoying - sometimes you see the message from IE itself and sometimes > How this has happened will take me some time to understand because the > line that says '404 not found' is followed - or I thought it was - by > an exit(); statement. > >> Either Firefox once got an invalid image and cached the response or the >> server does not respond the way you think. Maybe a BOM in the PHP file? >> This may not be visible in your editor, but it can cause all sort of >> problems. >> >> > Firefox makes it hard to debug because it DOES cache bad results: I > usually fix that by sending random nonsensical GET parameters which are > ignored to ensure it thinks its a different URL each time. > > It a huge minus against firefox that it didn't - even using the > debugging console - show me what was really going on, whereas IE6 did. You should learn to read HTTP response headers in the developer console of Firefox. When I open there the developer console of Firefox tells me EXACTLY what is going on: 1) The server responded with a status code 404 (not found) 2) The response contains a number of headers which are also displayed -- Arno Welzel http://arnowelzel.de http://de-rec-fahrrad.de