Improve redirect mechanism for merged terms

Subscribing. I suggest using Path_Redirect if available.

Initial patch that..

• creates path_redirect values for the taxonomy/term/[tid] URL of the $merging_terms,
• creates path_redirect values for any url_alias URLs of the $merging_terms,
• updates any existing path_redirect values that already existed to point to the $main_term.

That patch has an error in it. You need to change module_enabled('path_redirect') to module_exists('path_redirect')

With that change, the patch appears to do the right thing and is a welcome improvement.

Given that I also confirmed the incompatibility with Panels 3, I would suggest removing the existing redirect functionality entirely, and have the module just do a path_redirect by default instead (but still allow the checkbox to be unchecked). That would make path_redirect a prerequisite for this module, which would be fine.

Gah. I forgot to update the module with my local test code. Here's a corrected patch.

Thanks for the patch Damien. Maybe it would be useful to add a default option or omit the whole options thing. After all, it is the expected behaviour, when using the redirect module:

   if (count($options) > 0) {
     $form['merge']['options'] = array(
       '#type' => 'checkboxes',
       '#title' => t('Options'),
       '#options' => $options,
     );
+    if (module_exists('path_redirect')) {
+      $form['merge']['options']['#default_value'] = array('merge_redirect');
+    }

Thanks for the patch Damien and digi24.
I just make little fix - now patch works with new Path redirect module version 6.x-1.0-beta6. Please review.
Be careful, new version of Path redirect work only with Pathauto 6.x-1.x-dev.

Patch failed against 6.x-2.x-dev:

$ patch < taxonomy_manager.admin_.inc_.patch 
patching file taxonomy_manager.admin.inc
Hunk #1 succeeded at 573 (offset 1 line).
Hunk #2 FAILED at 2127.
1 out of 2 hunks FAILED -- saving rejects to file taxonomy_manager.admin.inc.rej

Adapted the patch to latest -dev, works fine for me.
Please review.

Patch from #9 works fine for me, just one "whitespace error":

path_redirect_6.patch:12: trailing whitespace.
$options['merge_redirect'] = t('Use path_redirect to redirect all old URLs to the new term.'); 
Checking patch taxonomy_manager.admin.inc...
Applied patch taxonomy_manager.admin.inc cleanly.
warning: 1 line adds whitespace errors.

Applied the last patch against the 6.x-2.2 with no errors or warning. Redirection now works fine!
Thank you very much!

Tried it again against dev and it works just fine. Patch output is this:

$ patch < path_redirect_6.patch 
patching file taxonomy_manager.admin.inc
Hunk #1 succeeded at 571 (offset -1 lines).
Hunk #2 succeeded at 585 (offset -1 lines).
Hunk #3 succeeded at 2131 (offset 1 line).

Can this be committed?

Confirming again that this works. RTBC