F3 + T does not reset the texture pack.

F3 + T doesn't reset the texture pack, it reloads it, and this feature is working well.

BTW: This ticket is incomplete; please review the guidelines before reporting issues.

Whenever I work on the items.png, then save, I go to Minecraft and do F3 + T. Nothing happens except for the text box opens along with the debug screen. I have to go change my texture pack, then change it back just to reload my texture pack and it has taken more time than you think.

• Created a test texture pack consisting of /pack.txt, /terrain.png and /gui/items.png.

• Started minecraft, selected test texture pack, going to creative mode

• Replaced /terrain.png and /gui/items.png and pressed F3 + C

• Voilá...

See my screenshots.

If I change the /gui/items.png in my texture pack, save, then go to minecraft, what do I have to do to update my texture pack without exiting my world?

• Do not zip your texture pack

• just create a folder JohnSmith or whatever

• copy the stuff inside

• Edit your files

• In Minecraft hold F3 and press T

• When you're done zip the contents of the folder as usual.

I was using MCPatcher. I clicked the 'unpatch' button on the MCPatcher program so that it would all be as if I had just barely updated. That was the entire problem! I apologize for all the trouble I've given you.
BTW, any idea when official support will come out for HD texture packs? Plz don't tell me it will be 1.6!