Lack of Weight Normalization causes problems with taxonomy_menu

I originally had this on Taxonomy menu but the more I looked into it, it's not taxonomy menu's fault, it's taxonomy manager which we're using to reorder the term order.

The weighting system is incompatible with Drupal's current method of weighting, which constrains weights between 50 and -50.

Hmm...I think this might do it.

In file: "updateWeight.js"
Replace Drupal.swapWeights with this one and add the two functions below it:

Drupal.swapWeights = function(upTerm, downTerm) {
  var upWeight = Drupal.getWeight(upTerm);
  var downWeight = Drupal.getWeight(downTerm);
  var downTid = Drupal.getTermId(downTerm);
  var upTid = Drupal.getTermId(upTerm);  
    
  if(upWeight > 50) {
    upWeight = 50;
  }
  if(downWeight > 50) {
    downWeight = 50;
  }
  if(upWeight < -50) {
    upWeight = -50;
  }
  if(downWeight < -50) {
    downWeight = -50;
  }
  //same weight, decrease upTerm
  if (upWeight == downWeight) {
    if(upWeight != -50) {
      weights[upTid] = --upWeight;
    }
    else {
      weights[downTid] = ++upWeight;
    }
  }  
  //different weights, swap
  else {
    weights[upTid] = downWeight;
    weights[downTid] = upWeight;
  }
  //update prev siblings if necessary
  try {
    if (Drupal.getWeight($(upTerm).prev()) >= upWeight) {
      $(upTerm).prevAll().each(Drupal.updateNextSiblingWeight(upWeight));
    }
  } catch(e) {
    //no prev
  }
  //update next siblings if necessary
  try {
    if (Drupal.getWeight($(downTerm).next()) <= downWeight) {
      $(downTerm).nextAll().each(Drupal.updatePrevSiblingWeight(downWeight));
    }
  } catch(e) {
    //no next
  }
}

Drupal.updateNextSiblingWeight = function (startWeight){
  var next = startWeight;
  function helper() {
    var id = Drupal.getTermId(this);
    weights[id] = --next;
  }
  
  return helper;
}

Drupal.updatePrevSiblingWeight = function (startWeight){
  var prev = startWeight;
  function helper() {
    var id = Drupal.getTermId(this);
    weights[id] = ++prev;
  }
  
  return helper;
}

It appeared to work when I tested it, however there were a few things that would cause the above code to go extremely wrong. I've rewritten it and everything seems to function great.

The following patch is against 6.x-2.x-dev.