TYPO3 Core

This seems to be related to issue http://forge.typo3.org/issues/34820

As stated in the comments of this issue, a regression for preview links has been introduced in TYPO3 4.5.12

A workaround I have found to broken page output due to mixing of http and https elements in the source is to adjust the baseurl according to the https status :

##In your constants
BASEURL = http://www.myhost.com/

[globalString = ENV:HTTP_HOST=www.myhost.com] AND [globalString =_SERVER|HTTPS=on]
BASEURL = https://www.myhost.com/
[global]

##In your setup
config.baseURL = {$BASEURL}

What about changing these in TYPO3\CMS\Backend\Utility\BackendUtility::getViewDomain($pageId, $rootLine = NULL)

if ($page['url_scheme'] == \TYPO3\CMS\Core\Utility\HttpUtility::SCHEME_HTTPS || $page['url_scheme'] == 0 && GeneralUtility::getIndpEnv('TYPO3_SSL')) {
    $protocol = 'https';
}

to

if ($GLOBALS['TYPO3_CONF_VARS']['BE']['lockSSL'] == 1 ||  $GLOBALS['TYPO3_CONF_VARS']['BE']['lockSSL'] == 2 || $page['url_scheme'] == \TYPO3\CMS\Core\Utility\HttpUtility::SCHEME_HTTPS || $page['url_scheme'] == 0 && GeneralUtility::getIndpEnv('TYPO3_SSL')) {
    $protocol = 'https';
}

Then every preview link is forced to use https if the backend is only available with https.

I can confirm this bug in TYPO3 4.5.30

but the behavior is weird...

Setup for baseUrl:

pageBase = http://www.mydomain.de/

[globalString = ENV:HTTPS=on]
    pageBase = https://www.mydomain.de/
[end]

[globalString = ENV:HTTP_HOST=cms.mydomain.de]
  pageBase = http://cms.mydomain.de/cms/
[end]

[globalString = ENV:HTTP_HOST=cms.mydomain.de] && [globalString = ENV:HTTPS=on]
        pageBase = https://cms.mydomain.de/cms/
[end]

the Backend is reached with https://cms.mydomain.de/cms/typo3/backend.php

in WORKSPACE preview this is set in the sourcecode:

<base href="https://cms.mydomain.de/cms/"></base>


which is correct, but all Links are generated like:

<a href="http://www.mydomain.de/some/path.html"></a>


Those links are not clickable in the browser.