0008716: Walls with suspended construction get invisible after cave in

Notes
(0031835) Detros (manager) 2015-01-10 04:17 edited on: 2015-01-10 05:09	First level: http://imgur.com/8R6RRqZ,7qJM7Bv#0 [^] Second level with invisible walls: http://imgur.com/8R6RRqZ,7qJM7Bv#1 [^] Save: http://dffd.wimbli.com/file.php?id=10409 [^] It may be connected to 0001205 also though that seems to really changed given tile while here it is rather graphical issue. Edit: After few game days, some of those invisible suspended-construction walls are now visible. It may have been caused by dwarves collecting those logs in construction area, I guess. Still at least one site is showing "log"/"blackness". I will go back to uploaded save and try to get the exact moment when those walls get visible again. If they don't show all soon, I will try moving to 40.24.

(0031867) Detros (manager) 2015-01-10 17:27	Yes, two tiles appeared after dwarf took away a log from one of them. Another showed itself once the construction was complete. But the fourth and, even a tile next to it (where neither wall nor its construction site was during that cave in) were a bit more weird: they also behaved normally once building was completed and on cancellation of building showed the right tile under them. BUT. Asking for another construction (tried walls, ramps and stairs) on those tiles made building-in-progress show again only blackness. I guess after all instead of current walls rather some tiles around that collapsed cliff got corrupted in an unusual graphical way.

(0031981) Detros (manager) 2015-01-18 03:40 edited on: 2015-01-18 03:40	I have got another occurrence a year or two later and in 40.24: one area near my main gate was collapsing every few months (trees around growing? who knows). After lose of the second dwarf to this, I started building roof from walls in that area so, when I am not sure why does cave ins happen, my dwarves will at least by covered. One of walls got suspended because of log of wood laying on its construction site. That tile was several times hit by cave in dust in last year but seemed to be normal till today. But then construction of that wall got suspended and now it is showing "log" and "darkness" while it should be switching between "log" and "wall". [q] and [k] still do work, as in the previous occurrence.

(0031982) Detros (manager) 2015-01-18 04:10	I have tried few more things and probably found it: it is caused by those gray "pile of sand" or "pile of sandy loam" that cave ins leave behind. I have tried all constructions (walls, ramps, stairs, tracks...) and they all behave the same: once you try to build them over a tile with this cave in sand they show as black tiles. And looking at what walls do when you build them over other types of tiles it seems to me it is clear now what does happen. Unfinished walls are showing their symbol in black and get background according to the tile below them. This background colour can be yellow for sand, white for grass, red for blood pools... or black for cave in sand piles. So that tile which I have considered to show "darkness" or an "invisible wall" in fact (AFAIK) shows "unfinished wall" as black "O" with black background for "pile of sand(y loam)".

Issue History
Date Modified	Username	Field	Change
2015-01-10 03:53	Detros	New Issue
2015-01-10 04:17	Detros	Note Added: 0031835
2015-01-10 05:09	Detros	Note Edited: 0031835	View Revisions
2015-01-10 12:42	Footkerchief	Relationship added	related to 0002588
2015-01-10 17:27	Detros	Note Added: 0031867
2015-01-18 03:40	Detros	Note Added: 0031981
2015-01-18 03:40	Detros	Note Edited: 0031981	View Revisions
2015-01-18 04:10	Detros	Note Added: 0031982
2015-06-27 14:49	lethosor	Relationship added	related to 0007496
2015-09-02 10:41	lethosor	Relationship added	parent of 0009056
2015-09-02 10:41	lethosor	Relationship replaced	related to 0009056