WARNING: ADDON IS BROKEN BY BLIZZARD PATCH, DEC 2006

Prevent a specific item or quality of items in bags from being sold to a merchant accidently. Credit for some of the code mentioned in changelog.

Instructions to prepare items to block:

Open window with /msl, use keybind, or visit a merchant and click on the icon at the top right corner of the merchant frame (icon box has no picture though)
Open your equipped bags.
Set the options.

Option description:

Enable option: enable/disable the addon.
BlockQuality option: prevent items from being sold that are equal or greater. For most cases, use 3 for rare.
BlockItems option: list of current items that are blocked.
AddByCursor option: add an item to list, by selectiong an item in the 5 equipped bags.
Add option: add name to the BlockItems list that is typed in the left box. (see notes below)
DeleteByCursor option: delete an item in list, by selecting an item from one of the 5 equipped bags.
Remove option: remove after highlighting the current item in the BlockItems list.
Reset option: erase BlockQuality and Blockitems.
Close option: close window.

When adding the name for an item manually, it must be spelled exactly and in full. Not case sensitive. Another possibility is to use wildcards, or so called patterns. That means that you can type '*' for any kind of text that should match the word. For example '*fish' would match with any phrase that ends with 'fish'.

Instructions when at merchant:

Automatically protects when at merchant and not need to open.
Right-click on an item in the 5 equipped bags to sell, as usual.
Message displayed in chat if item is blocked and not sold.
Press Alt and Right-click to override settings and sell any item, but will first confirm.
Optional to open window with /msl, use keybind, or click on the icon at the top right corner of the merchant frame (icon box has no picture though)

Command:

/msl
or, use keybind, 'MerchantSafeList Options Pane'

Options:

none, see window

Install:

Move the files to the game folder, .\World of Warcraft\Interface\AddOns\MerchantSafeList\*.*
Move the files to the game folder, .\World of Warcraft\Interface\AddOns\SupportFuncs\*.*
All settings are saved individually for each character in, .\World of Warcraft\WTF\Account\%accountname%\%playername%\SavedVariables\MerchantSafeList.lua

Uninstall:

Remove the game folder, .\World of Warcraft\Interface\AddOns\MerchantSafeList\*.*
Remove the game folder, .\World of Warcraft\Interface\AddOns\SupportFuncs\*.* (if not used by other addons)
Remove the variable file, .\World of Warcraft\WTF\Account\%accountname%\%playername%\SavedVariables\MerchantSafeList.lua

Credit goes to some code from old addons that were not being updated, myMerchantSafe, AutoBagAdopted.

Todo:

Add names to block list from anywhere, like character window, bank, etc.
Report which items in bags are not protected yet so we can protect them if we want. Find a way to report on character, bank, etc. too. Report on items that no longer exist on character. For immediate verification, change color of icons in bags to gray when protected and window is open.

Known bugs:

Icon at the top right corner of the merchant frame has no picture. It is a blank dark box that is hard to see. I was unable to add a texture.

Known limitations:

Can only add items to the blocked list from the 5 equipped bags, and not from equipped character window, bank, etc. All items must be moved first to the bags and choose the AddByCursor option. Or do not move and just type in the name of the item and choose the Add option.
Can only sell items from the 5 equipped bags. This is a limitation by blizzard.
The item name added to the list must be spelled correctly and in full. Not case sensitive though. Exception is when using wildcard.
Not tested with other bag addons.
Not tested with other addons that also affect the merchant.

ChangeLog:

Release version 1.1

(web site erased all my previous changelog info :()

MerchantSafeList