this is a really easy question. present trunks is future trunks, the movie doesn't tie in with the TV series timeline, but with the alternate timeline, the one of trunks future(androids kill everything and stuff).

Let me take a crack at this question: Future Trunks (from the Androids Destroy Everything timeline)
got his sword from Son Gohan in that same future as a last request (as 17 and 18 killed him). Trunks from the main timeline got his sword from Taipon. I hope that cleared things up.

Man, DBZ continuity is so fucked up, as far as the movies are concerned. I realized this when I watched Cooler's Revenge.

...And, naturally, my answer is swept under the rug, for the sake of ambiguity...

cartoons don't have to be 100% realistic.

Each movie represents a divergence from the timeline, otherwise they would be impossible. Except for Dead Zone, which they integrated in via the Garlic Jr saga, and could have happened anyway if you look at the timeline.

So the sword is probably unrelated.

This.

I think its coincidence that the swords look alike, or probably the movie creators said something like "oh, lets make tapion give him  his sword, OH AND LETS MAKE IT LIKE THE ONE HIS VERSION OF THE FUTURE HAD SO THAT WAY IS COOLER" or something like that.

It would match because in the series Trunks explains that no matter what he did in that time, it wouldnt change his own timeline, meaning that both universes share  a lot of things but they differ in some like these too, especially after the series timeline was "changed" by future Trunks going there and that would explain possible differences.

Another, and very probable thing, is that its a mistake and they didnt ask the question you asked to us to themselves when they made it. Meaning that its a plot hole or something like that.

Anyway you take it its valid I think until the movie or series creator speaks what is their truth about the thing, but they wll probably say:"oh, we didnt notice the problem with that, well, it doesnt even matter".

Good question Gar, never did figure it out here to, one of the many reasons why i dislike DBZ and anything Dragon ball now and days.

I only got that dragon ball game for PS3 because my dad still loves it for whatever reason but its story is even more broken then Kingdom Hearts.

I gave it to him.

Another question, why did Goku ever get upset if anyone died? He always could just wished them back.

Another one, why didnt Goku or the Z warriors...just WISH away the villians. Would of made the show much better.