Can't paste lyrics into tuplet

I was using the MuseScore official release. I've now repeated the experiment with the most recent nightly for mac (2015-03-27-1017-a249aea.dmg), and with that I get the same result as you, I get the error message "can't paste into tuplet" for seemingly any tuplet. I guess that's a bit of an improvement over not getting any message.

I've noticed that the problem however is not limited to lyrics. It also applies to notes. If I copy any sequence of notes (including, possibly, tuplets) and click on any note anywhere in a score except a tuplet, I can paste that sequence of notes starting at that position. But I can't do it if the note I click on to start the paste is part of a tuplet; I get the same error message "cannot paste into a tuplet".

This restriction is peculiar -- there seems to be no problem pasting into a tuplet so long as the paste doesn't START in the tuplet. In fact MuseScore may well proceed with something incorrect in that case: For example, paste a sequence [quarter note - eighth note] into a sequence [quarter note - triplet of eighth notes]. The result seems to be a quarter note followed by an eighth followed by the third of the original triplets -- leaving out 1/6 of a beat. See the attached pdf file, where I pasted the two notes of the top staff into the middle staff, and the result is what is shown in the bottom staff.

A problem with the adopted approach RE pasting into triplets is that it arbitrarily rejects pasting some material into a note in the tuplet, but not a longer sequence that ends with the identical copied material and the identical paste target as subsets. So I would think that any musically illegal operation that has been excluded by the "can't paste into tuplets" rule can still be made to happen. Yes I will file a separate bug report, which will include repeating the previous two sentences.

Meanwhile I hope the restriction will be relaxed for lyrics at least. I can imagine quite a few use scenarios where one would like to be able to paste lyrics into triplets. Example, polyphonic choral music, where one or more voices have a phrase starting with a triplet, and the voices share common lyrics, possibly staggered, but rigorously one syllable per note. One would like to be able to enter lyrics for one voice, copy, and paste into the other voices. As things stand now I would have to first enter the lyrics for the voice that starts with the triplet, then copy/paste into the other voices. And if one of those other voices ALSO starts with a triplet, I'm out of luck.

In thinking further I don't see why the restriction should be there at all. Looking at your examples, there is a legitimate (though not pretty) thing to do in each case. For pasting a half note into, say, the second note of an eighth note triplet, the result should be an eighth + quarter note triplet consisting of the original first eighth note plus a quarter note at the pitch of the copied half note, with the latter tied to a (non-triplet) quarter note at the pitch of the copied half note, tied to a triplet-ized eighth note. (If what was in the last position was a quarter note, this triplet-ized eighth note would be under a triplet bracket with a quarter note at the same pitch as the pre-paste quarter note; if what was in that position was an eighth note, then the triplet-ized eighth note would be under a half-beat triplet with the remaining portion of the pre-paste eighth note, which would now be a triplet 16th note.) Quite generally, the image of the paste extends to a well-defined and notatable portion of a note in the pre-paste music. It seems that MuseScore should be able to "do the math", and hence replace notes that are fully subsumed by the paste with the pasted material, and a final note that is partly subsumed by the paste with the end of the pasted material plus the appropriate fraction of the original note. Same principle applies to your part-of-a-quintuplet example.

OK, challenge accepted! I have been intending, for over a year, to start making some contributions (other than bug reports) to MuseScore, but other things have gotten in the way. I'm up to my ears for the next month, but If someone hasn't tackled this by May I'll see if I can learn my way around well enough to contribute something. But my basic concern is that the present restriction really doesn't solve anything, since any mischief one could do by starting to paste in a triplet could equally well occur as part of a longer paste starting before the triplet.

It seems to me that for any bad situation you precluded involving a paste that starts in the middle of a tuplet and extends beyond the end of the tuplet, there is (to borrow a word from serial music) the retrograde situation -- a mirror image paste that starts before the tuplet and ends in the middle of it with exactly the same problem. Right now you don't disallow any such paste.

Maybe the easiest fix that would allow most "legal" situations is, rather than to exclude any paste that starts anywhere within a tuplet, is to check to see if a paste starts or ends in the middle of a tuplet and just disallow those. In particular allow pastes that start on the beginning of a tuplet OR before the tuplet so long as they extend to at least the tuplet's end. I appreciate that there is a potential problem of a paste that would end in the middle of the last note of a tuplet -- e.g. pasting 4 notes of a quintuplet into a triplet, starting with the first note of the triplet -- so the check has to be that the paste extends fully to, or beyond, the end of the target tuplet. (That's a potential problem with the current coding as well.)