It would be really cool to have this feature as mentioned...the ability to have a custom field be a textbox/textarea just like the required fields "Additional Information", "Description" and the "Bug Notes". I was looking at the code and the database setup, because I was thinking about changing it for myself to use, but the only way I could see was to either change the table where custom field data was stored to to have this text be a text value instead of varchar(255), which limited it to a single line of 256 characters. I hesitate to do this, because I figure that will possibly hinder me upgrading easily later on..

So yeah, I'm wondering as well if there is any planning for this to be added/enabled in any future versions (hopefully soon :))?? It would be immensely useful.

It would be extremely helpful for things like I was hoping to implement textarea custom fields for: Testing Commments (testing steps for fixes), Technical Investigation notes, pasting in emails or technical discussions, pasting in snippets of source code (oddly, it really would be useful).

This is just to confirm that I have exactly the same need and would be very happy to be able to define custom fields as textarea.

I would also like this feature to be added. We have to answer a number of questions (e.g. installation steps, backout plan etc.) for a "Product Change Order", and being able to retrieve these answers directly from Mantis would be a godsend !!!!

I would also like this feature.
Currently you can use a textarea with 255 characters, just follow these steps:

1. core/custom_field_api.php
   function print_custom_field_input
   case CUSTOM_FIELD_TYPE_TEXTAREA:
   echo '<textarea name="customfield' . $t_id . '" cols="60" rows="5" wrap="virtual"';
   if(0 < $p_field_def['length_max'] ) {
   echo ' maxlength="' . $p_field_def['length_max'] . '"';
   } else {
   echo ' maxlength="255"';
   }
   echo " value=\"$t_custom_field_value\">". nl2br($t_custom_field_value). "</textarea>";
   break;

2. config_inc.php
   $g_custom_field_type_enum_string = '0:string,1:numeric,2:float,3:enum,4:email,5:checkbox,6:list,7:multiselection list,8:date,9:textarea';
3. custom_strings_inc.php
   $s_custom_field_type_enum_string = '0:String,1:Numeric,2:Float,3:Enumeration,4:Email,5:Checkbox,6:List,7:Multiselection list,8:Date,9:Textarea';
4. custom_constant_inc.php

   custom Field types

   define( 'CUSTOM_FIELD_TYPE_TEXTAREA', 9 );

I am also very interested in this feature.
I implemented illes patch and it works great, thanks.
I just replaced nl2br($t_custom_field_value) with $t_custom_field_value
because extra line break were added each time I updated an issue.

This functionality won't change in 1.0, however, as part of changes I might look at adding for 1.1, i'll see if we can change the database field from varchar(255) to something larger.

Great, I'm looking forward to it!

I needed the textarea custom field too, so my workaround included hacking the custom_field_api.php file, and also changing the database schema to include a new table. The new table has the same structure as the mantis_custom_field_string_table, except for the value field which has TEXT data type.

Some more additional hacking in custom_field_api.php (in addition to those mentioned by illes), to select the correct custom field table to use by detecting the custom field type:
custom_field_get_value function
custom_field_set_value function
string_custom_field_value function (since it calls the custom_field_get_value function)

A simpler solution (one could say "hack") is with a patch in 0005679

eurayle, can you provide your patch ?

Since we needed long text custom fields (textareas) we tried the same king of solution that illes wrote on 05-04-11 08:40.
We use Mantis on a mySQL 4.1.9 database. To allow long texts, we modified the database schema for 3 fields (standard SQL command that does not erase existing data) :
ALTER TABLE mantis_custom_field_table MODIFY possible_values TEXT NOT NULL;
ALTER TABLE mantis_custom_field_table MODIFY default_value TEXT NOT NULL;
ALTER TABLE mantis_custom_field_string_table MODIFY value TEXT NOT NULL;

All works fine since 4 days now on our test server, maybe you have any ideas of problems those modifications could lead to...

I tried to do the same as nyhgo, going into the database and changing the type of the field, but I am still be capped at 511 characters. There seems to be something else limiting the the size of fields, since a text should hold 65,535 characters.

We are "upgrading" from a MS Access DB containing some 900 bug reports to Mantis 1.2.0, which, I am sure, will facilitate our work a lot. The Access DB contains several text fields with more than 500 characters, thus a feature like CUSTOM_FIELD_TYPE_TEXTAREA is required (also for new bug reports). A limit of 511 characters would be acceptable, although truncation of the original texts would occur in some cases. However, the extensions used by illes and others seem not to be applicable in Mantis 1.2.0. Before trying a hack (with, as a beginner, limited knowledge of Mantis), which will complicate future Mantis upgrades: are there plans to implement custom text fields or textareas with more than 255 (preferentially some 1023) characters in the near future?