Breeze plugin injects unexpected characters into output buffer

  • Resolved typeless

    (@jbalyo)


    7 months, 1 week ago

    When Breeze is enabled – even if its features remain disabled – it messes up the php://output stream by inserting extra characters at the beginning of the output buffer. This ends up corrupting exported files such as those generated with the phpoffice library.

    ob_clean() and ob_end_clean() has no effect and does not clear the output buffer like normal. Somehow Breeze is injecting the characters regardless.

    For example:

    $objWriter = IOFactory::createWriter($objExcel, 'Xlsx');
    ob_end_clean();
    $objWriter->save('php://output');

    When Breeze is enabled, this injects extra characters or spaces at the beginning of the output stream even though the output buffer was cleared immediately prior. These characters corrupt the resulting file.

    Without Breeze enabled, the output buffer is unaltered and the resulting file is valid.

    Any solution or workaround for this?

Viewing 5 replies - 1 through 5 (of 5 total)
  • Thread Starter typeless

    (@jbalyo)

    I figured out the two characters it is injecting are ASCII 013 and 010 – which of course is CR LF (Carriage Return & Line Feed).

    Plugin Author owaisalam

    (@owaisalam)

    Thank you for highlighting this point. I will discuss the mentioned issue with the Breeze engineering team to get a better understanding and provide you with a comprehensive response. I’ll get back to you as soon as I have more information.

    Plugin Author owaisalam

    (@owaisalam)

    First of all, thank you for your patience.

    Our engineering team attempted to replicate the scenario to print data in XLSX file format but were unsuccessful. The process works perfectly with Breeze.

    To further investigate, could you please share your Breeze settings? Additionally, it would be helpful if you could verify if there are any errors or warnings generated at your application level. These might help us identify the point of conflict.

    It is possible that the issue could be due to conflicts with activated themes or plugins, or any custom functionality applied at the application level. Identifying any such conflicts will help us better understand the problem and provide a more accurate solution.

    Thank you for your cooperation.

    • This reply was modified 7 months ago by owaisalam.
    Thread Starter typeless

    (@jbalyo)

    Thank you for your reply. I found a workaround on my own, so the below is provided for your developers in case they wish to investigate further.

    When Breeze is enabled, the CRLF gets inserted into the output buffer. When Breeze is disabled, the character disappears, so it seems reasonable to assume it is something Breeze is doing, though I’m not sure what that would be. In my experience this type of thing is usually caused by a blank line left outside of the PHP brackets in a place where it shouldn’t be, but I scanned the plugin code and didn’t find anything like that – nothing obvious anyway. I also tried other cache plugins to see if it is just cache in general, but they did not produce the same behavior.

    There are no related PHP errors as it isn’t really an error at all – just a malformed output buffer. I’ll provide my Breeze settings below, but again, it seems to inject the character no matter what settings we use – even with all features disabled. I tried many combinations of settings, and even tried adding the page in question to the Excluded URLs list at one point.

    Here’s my workaround which forcefully removes the stray character from the output buffer.

    // save output buffer to a variable so we can manipulate it
    ob_end_clean();
    ob_start();
    $objWriter->save('php://output');
    $content = ob_get_contents();
    ob_end_clean();

    // get rid of stray CRLF
    $content = ltrim($content, "\r\n");

    echo $content;

    Breeze settings (api-token removed):

    {"breeze_basic_settings":{"breeze-active":"1","breeze-mobile-separate":"0","breeze-cross-origin":"0","breeze-disable-admin":{"administrator":0,"author":0,"contributor":0,"editor":0,"subscriber":0,"wpseo_manager":0,"wpseo_editor":0},"breeze-gzip-compression":"1","breeze-browser-cache":"1","breeze-lazy-load":"0","breeze-lazy-load-native":"0","breeze-lazy-load-iframes":"0","breeze-lazy-load-videos":"0","breeze-desktop-cache":"1","breeze-mobile-cache":"1","breeze-display-clean":"1","breeze-b-ttl":1440},"breeze_advanced_settings":{"breeze-exclude-urls":[],"cached-query-strings":[],"breeze-wp-emoji":"0","breeze-store-googlefonts-locally":"0","breeze-store-googleanalytics-locally":"0","breeze-store-facebookpixel-locally":"0","breeze-store-gravatars-locally":"0","breeze-enable-api":"0","breeze-secure-api":"0","breeze-api-token":"******"},"breeze_heartbeat_settings":{"breeze-control-heartbeat":"0","breeze-heartbeat-front":"","breeze-heartbeat-postedit":"","breeze-heartbeat-backend":""},"breeze_cdn_integration":{"cdn-active":"0","cdn-url":"","cdn-content":["wp-includes","wp-content"],"cdn-exclude-content":[".php"],"cdn-relative-path":"1"},"breeze_varnish_cache":{"auto-purge-varnish":"1","breeze-varnish-server-ip":"127.0.0.1"},"breeze_first_install":"no","breeze_preload_settings":{"breeze-preload-fonts":[],"breeze-preload-links":"1","breeze-prefetch-urls":[]},"breeze_file_settings":{"breeze-exclude-urls":[],"cached-query-strings":[],"breeze-wp-emoji":"0","breeze-store-googlefonts-locally":"0","breeze-store-googleanalytics-locally":"0","breeze-store-facebookpixel-locally":"0","breeze-store-gravatars-locally":"0","breeze-enable-api":"0","breeze-secure-api":"0","breeze-api-token":"******"},"breeze_ecommerce_detect":false,"breeze_advanced_settings_120":"yes"}
    Plugin Author owaisalam

    (@owaisalam)

    Thank you very much for your detailed description; it helps a lot in further debugging. We will definitely continue to investigate this issue and plan to include any necessary fixes in our upcoming releases.

Viewing 5 replies - 1 through 5 (of 5 total)
  • The topic ‘Breeze plugin injects unexpected characters into output buffer’ is closed to new replies.