cache not clearing in _geshifilter_get_tags

Hi

I'm working on a patch for geshifilter (I haven't created an issue for it yet but will shortly). In the process of doing this, I ran into some unexpected behavior in my patch. My patch calls _geshifilter_get_tags but doesn't seem to be getting the right values returned.

For example, I have 2 input formats, filtered HTML and unfiltered HTML. For both of those filters geshifilter is enabled. At admin/settings/geshifilter I have checked "Seperate settings per input format".

The relevant settings for the two input formats as displayed in the config web based GUI are as follows:
Filtered HTML:
Generic syntax highlighting tags: cpp ccode code
per language tags:
c-->ccode
c++-->cpp
css-->html

Unfiltered HTML:
Generic syntax highlighting tags:
per language tags:
c-->ccode
c++-->cpp
html4strict-->html

Note that the language that the "html" language code is attached to is different. I realize that these assignments are sort of nonsense, but they are what I had.

Now, if I edit _geshifilter_get_tags and add the following line just before the return statement:

print_r($geshifilter_tags_cache);

and if I call _geshifilter_get_tags from the patch I'm working on, I get this output:

Array
(
    [0] => Array
        (
            [0] => cpp
            [1] => ccode
            [2] => code
        )

    [1] => Array
        (
            [0] => ccode
            [1] => cpp
            [2] => html
        )

    [2] => Array
        (
            [ccode] => c
            [cpp] => cpp
            [html] => css
        )

)
Array
(
    [0] => Array
        (
            [0] => cpp
            [1] => ccode
            [2] => code
        )

    [1] => Array
        (
            [0] => ccode
            [1] => cpp
            [2] => html
        )

    [2] => Array
        (
            [ccode] => c
            [cpp] => cpp
            [html] => css
        )

)

This doesn't look right to me, as both input formats are giving the same values for the tags used.

If I modify _geshifilter_get_tags (to remove the static variable) so it looks like this:

function _geshifilter_get_tags($format) {
//  static $geshifilter_tags_cache = NULL;
//  if ($geshifilter_tags_cache === NULL) {
    $generic_code_tags = _geshifilter_tag_split(geshifilter_tags($format));
    $language_tags = array();
    $tag_to_lang = array();
    $enabled_languages = _geshifilter_get_enabled_languages();
    foreach ($enabled_languages as $language => $fullname) {
      $lang_tags = _geshifilter_tag_split(geshifilter_language_tags($language, $format));
      foreach ($lang_tags as $lang_tag) {
        $language_tags[] = $lang_tag;
        $tag_to_lang[$lang_tag] = $language;
      }
    }
    $geshifilter_tags_cache = array($generic_code_tags, $language_tags, $tag_to_lang);
//  }
print_r($geshifilter_tags_cache);
  return $geshifilter_tags_cache;
}

and then I reload the same page and look at what is printed, I get this (which appears to be correct):

Array
(
    [0] => Array
        (
            [0] => cpp
            [1] => ccode
            [2] => code
        )

    [1] => Array
        (
            [0] => ccode
            [1] => cpp
            [2] => html
        )

    [2] => Array
        (
            [ccode] => c
            [cpp] => cpp
            [html] => css
        )

)
Array
(
    [0] => Array
        (
        )

    [1] => Array
        (
            [0] => ccode
            [1] => cpp
            [2] => html
        )

    [2] => Array
        (
            [ccode] => c
            [cpp] => cpp
            [html] => html4strict
        )

)

I'm pretty sure that the patch I'm working on has nothing to do with this, since all of that code is in the function geshifilter_admin_filter_conflicts(). Can you take a look at this and either try to fix _geshifilter_get_tags so that it returns the right values or explain to me what's going on with the code and where my thinking has gone wrong.

BTW, I tried clicking the link on the help page to clear the cache (/drupal/geshifilter/clearfiltercache?destination=admin%2Fhelp%2Fgeshifilter) and that didn't change anything.