Theme hook suggestions are not inheriting base hook preprocess functions

Pretty sure this is a duplicate of this related issue.

Hm. Ok. It still sounds like it's related to this D8 issue though.

I'll have to step through the registry/theme invocation in more detail. It may be an issue with the registry alter (not picking up the file for preprocess suggestions?).

The ultimate reason I closed this is because the patch in #2 should not be necessary. Preprocess functions are accumulative (meaning the base preprocess should always run first) and this patch would essentially "double" preprocess a button.

Essentially, the majority of _bootstrap_process_theme_registry_suggestions() needs to come out... or at the very least severely refactored so just adds in the discovered base theme hook files.

edit: also, please keep in mind that the code in registry.inc is still heavily based on 7.x.

I was seeing this also, so I've merged this which does fix the issue. Guess that preprocess wasn't being fired in the past...

Reverting this commit until the issue that caused button labels can be addressed.

I will try and cleanup the registry.inc file this weekend.

I have traced the issue and have suggesting working once again there maybe some clean up we could do the issue was introduced by #939462: Specific preprocess functions for theme hook suggestions are not invoked because of changes to how the registry is build. The fix just updates the bootstrap module but I was able to also fix it by changing

// Discover and add all preprocess functions for theme hook suggestions.
$this->postProcessExtension($cache, $this->theme);

// Let modules and themes alter the registry.
$this->moduleHandler->alter('theme_registry', $cache);
$this->themeManager->alterForTheme($this->theme, 'theme_registry', $cache);

Too

// Let modules and themes alter the registry.
$this->moduleHandler->alter('theme_registry', $cache);
$this->themeManager->alterForTheme($this->theme, 'theme_registry', $cache);

// Discover and add all preprocess functions for theme hook suggestions.
$this->postProcessExtension($cache, $this->theme);

This off course means that we lose the ability fully alter the registry and brings into question do we need an alter.

Solution looks OK and it seems to fix the issue. When reviewing this I thought how much nicer would this be if we'd extent core's registry service and add bootstrap's stuff there. This will give us access to protected functions like postProcessExtension() etc.

I am aware this is module material, but so complex registry alter probably belongs there anyway.

Fixes a notice at install time

Merged.