cant work with term named 0 (zero)

I confirm this bug.

An obvious workaround is to

UPDATE `db`.`term_data` SET `name` = '0' WHERE `term_data`.`tid` = [tid];

but im not sure if that will be very resilient if you for example change the order of terms, and the deleting mechanism comes in force.

Dont forget to update the url alias too.

random exstinguishing a term seems like a big bug to me > upscaling.

This works ok on D7 -- this is a D6 only bug, which is one thing at least :)

Please review the meaning of the Status values -- 'needs work' means there is a patch, and there isn't.

Thanks, have reviewed the meaning of the status values, I see that I got it wrong there. I thought 'needs work' meant it had been confirmed that there is something that could do with being fixed in the project.

Yes the same problem i have also faced.
I have changed the code for taxonomy.module file:

Under
function taxonomy_save_term(&$form_values) {
please find the line: if (!empty($form_values['tid']) && $form_values['name']) {

changed the code from
if (!empty($form_values['tid']) && $form_values['name']) {
to
if (!empty($form_values['tid']) && isset($form_values['name'])) {

The above solution solved my problem.

There are several bugs in Drupal where it assumes that empty() returns TRUE only for null or '' (empty string). However several other things also return TRUE - see http://php.net/empty

"" (an empty string)
0 (0 as an integer)
0.0 (0 as a float)
"0" (0 as a string)
NULL
FALSE
array() (an empty array)
$var; (a variable declared, but without a value)

I believe I did an audit of the code for this several years ago, in a d.o issue, but it hasn't progressed since then.