How to force Chrome NOT to cache redirects?

Question

A simple HTML code:

<img src="http://someaddr/image.php">

image.php is a script that returns a random Redirect to a static image with all necessary no-cache headers:

Cache-Control: no-cache, no-store, must-revalidate
Pragma: no-cache
Expires: 0
Location: http://someaddr/random_image_12345.jpg

The problem: when navigating back and forward to this HTML page, Chrome (latest win/mac) does not revalidate address http://someaddr/image.php.

I have tried using redirects 302 and also 303 (which in RFC has stronger requirement that it should NEVER been cached by browser). This works like a charm in IE, FireFox, Opera. They always refresh http://someaddr/image.php. But Chrome doesn't.

I have even used Developer Tools in Chrome, and it seems that in Network Log it even don't shows any attempt (cached or not) of fetching http://someaddr/image.php. Network Log shows only one connection already to http://someaddr/random_image_12345.jpg (cached). Why this is so broken...

I know the naive/simple solution of putting query string in image source:

    <img src="http://someaddr/image.php?refresh={any random number or timestamp}">

But I don't like/can't use hacks like that. Are there ANY other options?

Answer 1

From a link posted in another question:

 The first header Cache-Control: must-revalidate means that browser must send validation request every time even if there is already cache entry exists for this object.
Browser receives the content and stores it in the cache along with the last modified value.
Next time browser will send additional header:
If-Modified-Since: 15 Sep 2008 17:43:00 GMT

This header means that browser has cache entry that was last changed 17:43.
Then server will compare the time with last modified time of actual content and if it was changed server will send the whole updated object along with new Last-Modified value.

If there were no changes since the previous request then there will be short empty-body answer:
HTTP/1.x 304 Not Modified

You can use HTTP's etags and last modified dates to ensure that you're not sending the browser data it already has cached.

$last_modified_time = filemtime($file); 
$etag = md5_file($file); 

header("Last-Modified: ".gmdate("D, d M Y H:i:s", $last_modified_time)." GMT"); 
header("Etag: $etag"); 

if (@strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) == $last_modified_time || 
    trim($_SERVER['HTTP_IF_NONE_MATCH']) == $etag) { 
    header("HTTP/1.1 304 Not Modified"); 
    exit; 
} 

Answer 2

Try a 307 redirect

But if you're stuck trying to get to a link that won't work due to a cached redirect...

This doesn't clear the cache but it's one quick and possible route around it if you're pulling your hair out trying to get to a link that has been redirect cached.

Copy the link address into the address bar and add some GET information to the address.

EXAMPLE If your site is http://example.com

Put a ?x=y at the end of it 
( example.com?x=y ) - the x and y could be anything you want.

If there is already a ? in the url with some info after it

( example.com?this=that&true=t ) - try to add &x=y to the end of it...

( example.com?this=that&true=t&x=y )