One of the commerce packages noted that one of the extension modules required enabling PHP short_tags. I had previously disabled php short_tags because it was preventing the use of the xml declaration tag at the top of my html files.
I use XHTML 1.1 for all my HTML work. Converting every document I do significant work on to XHTML 1.1. So turning back on PHP short_tags in my HTML files was not an option.
Luckily that was not necessary. I have enabled the PHP handler for .html and .xhtml files in my php5.conf located in /etc/apache2/conf.d/. I have a few other PHP related configuration statements that are wrapped by an if module mod_php statement.
I created a Files section within that if module mod_php that disables short tags only within .html and .xhtml files. Like so:
AddHandler application/x-httpd-php .html .xhtml
<Files ~ "\.x?html$">
php_flag short_open_tag off
Alias /phpinfo /var/www/phpinfo.php
Alias /apcinfo /usr/share/php/apc.php
I also have a couple of aliases in there that make useful system info URLs available automatically on all web hostnames. The PHP Alternative Cache, APC, has builtin PHP login security. I'm going to add PHP authentication to the phpinfo and post the code.