Building on my previous answer: http://www.question2answer.org/qa/55614/how-to-make-it-impossible-to-remove-the-upvote?show=55618#a55618
There is no setting to do so. You'll have to modify code. This can be done with a layer (or even modifying the theme) and an override. However, here are the corehacks with the changes.
1. Edit qa-include/qa-theme-base.php
2. Locate function vote_buttons and edit it this way (this sets up the user interface and is just for cosmetic purposes):
Turn this:
case 'voted_down':
$this->post_hover_button($post, 'vote_down_tags', '–', 'qa-vote-one-button qa-voted-down');
break;
case 'voted_down_disabled':
$this->post_disabled_button($post, 'vote_down_tags', '–', 'qa-vote-one-button qa-vote-down');
break;
case 'up_only':
$this->post_hover_button($post, 'vote_up_tags', '+', 'qa-vote-first-button qa-vote-up');
$this->post_disabled_button($post, 'vote_down_tags', '', 'qa-vote-second-button qa-vote-down');
break;
case 'enabled':
$this->post_hover_button($post, 'vote_up_tags', '+', 'qa-vote-first-button qa-vote-up');
$this->post_hover_button($post, 'vote_down_tags', '–', 'qa-vote-second-button qa-vote-down');
break;
default:
$this->post_disabled_button($post, 'vote_up_tags', '', 'qa-vote-first-button qa-vote-up');
$this->post_disabled_button($post, 'vote_down_tags', '', 'qa-vote-second-button qa-vote-down');
break;
Into this (just add the double slashes):
case 'voted_down':
// $this->post_hover_button($post, 'vote_down_tags', '–', 'qa-vote-one-button qa-voted-down');
break;
case 'voted_down_disabled':
// $this->post_disabled_button($post, 'vote_down_tags', '–', 'qa-vote-one-button qa-vote-down');
break;
case 'up_only':
$this->post_hover_button($post, 'vote_up_tags', '+', 'qa-vote-first-button qa-vote-up');
// $this->post_disabled_button($post, 'vote_down_tags', '', 'qa-vote-second-button qa-vote-down');
break;
case 'enabled':
$this->post_hover_button($post, 'vote_up_tags', '+', 'qa-vote-first-button qa-vote-up');
// $this->post_hover_button($post, 'vote_down_tags', '–', 'qa-vote-second-button qa-vote-down');
break;
default:
$this->post_disabled_button($post, 'vote_up_tags', '', 'qa-vote-first-button qa-vote-up');
// $this->post_disabled_button($post, 'vote_down_tags', '', 'qa-vote-second-button qa-vote-down');
break;
3. Edit file qa-include/app/votes.php
4. Locate function qa_vote_set and add this:
if ((int)$vote === -1) {
return;
}
Before this line:
require_once QA_INCLUDE_DIR.'db/points.php';
