Making split hunks addable

Inizia leggendo le sezioni collegate del documento alle righe 86-89 e 212-217. Il lavoro è completato quando gli hunk divisi conservano informazioni sufficienti sulle righe originali per poter essere ricombinati, inclusi gli hunk divisi ricorsivamente, mentre la corrispondenza degli hunk considera l’intersezione e la similarità degli intervalli di righe.

https://github.com/gitbutlerapp/writeups/blob/6261a226a284a568060cca21debcffdf05cfaf84/230901-sc-vb-sub-hunks.md?plain=1#L86-L89

The problem as I understand it is that it's easy to separate a diff into two the way github desktop does it, but putting them back together doesn't work.. But what if we only needed to store and cascade the original line number when splitting diffs to make them addable again?

As an example, if we split this:

@@ -1,4 +1,7 @@
 a
 b
+c
+d
+e
 f
 g

into these two:

@@ -1,4 +1,5 @@
 a
 b
+d // original line 4
 f
 g

@@ -1,4 +1,6 @@
 a
 b
+c  // original line 3
+e  // original line 5
 f
 g

Then we have enough information to reverse the split? It works even if we split the second diff into two again.

https://github.com/gitbutlerapp/writeups/blob/6261a226a284a568060cca21debcffdf05cfaf84/230901-sc-vb-sub-hunks.md?plain=1#L212-L217

Also, about matching up the hunk ranges properly. I don't think we do a good enough job right now, but with a bit of effort we could have something quite solid that matches based on both line range intersection as well as the similarity score @Qix- coded up a while back.