Comment author: till

The problem seems to be in the code that merges the locations. A simpler test of appears to be the same bug would be:

tmp> cat t.ml
type t = int
tmp> camlp4o t.ml -add_locations
(loc: ["t.ml": 1:0-12 1:12])
type (loc: ["t.ml": 1:5-12 1:12])
t =
(loc: ["ghost-location": 1:9-0 1:0 (ghost)])
(loc: ["ghost-location": 1:9-0 1:0 (ghost)])
(loc: ["ghost-location": 1:9-0 1:0 (ghost)])
int

The attached patch should fix this.

Comment author: @ygrek

Hm, am I the only one to think that { (b) with stop = b.stop } is waste of characters (whatever b is)?

Comment author: till

Indeed. That's because this line should have been:
{ (b) with start = a.start }
That's a bit embarrassing for a patch this small. Uploaded a corrected patch.

Comment author: till

It turns out that keeping the ghost=True in the resulting location is also important (although I couldn't really figure out where it was used in camlp4). Hopefully that's the last regression on that bug fix. I'll upload a patch with the bootstrapping soon.

Comment author: till

Seems fixed in the 3.12 svn (at least for my problem cases).

Comment author: @damiendoligez

The second problem is fixed in 3.12.1 and the first one in 4.00.0.