on level 24, we have (near (21|51)) 3 (unanimated) signs with the labels

idx=529 type=32 data={
	question mark sign
}
idx=530 type=32 data={
	exclamation mark sign
}
idx=531 type=32 data={
	less than sign
}


since the signs were added to the map, obstacles got removed in

commit a1c0e65b670b0fc731b1076d84c71f01e9a07d18
Author: matthiaskrgr <matthiaskrgr@524c2bfb-fa3f-0410-b5a2-92f4e1dc5b61>
Date:   Fri Dec 23 10:53:43 2011 +0000

    obstacles: remove obstacle 62, ISO_H_DENSE_FENCE.



and


commit b288109dcbf7d6fb245175c35392d852006d0a4b
Author: matthiaskrgr <matthiaskrgr@524c2bfb-fa3f-0410-b5a2-92f4e1dc5b61>
Date:   Fri Dec 23 09:59:18 2011 +0000

    obstacles: remove ISO_V_DENSE_FENCE, obstacle 61.


these obstacles were most likely replaced by dummy_obstacles in
obstacle_specs.lua, and I removed them from level 24.

The removal of these two obstacles seems to have caused the shifting of the map
labels by two obstacles; the question- and exclamation-mark-signs have no more
descriptions at all (although the descriptions are still in the mapfile) and the
less-then-sign has the description of the first sign and now says "question mark
sign".



Whatever happens, sign messages are NOT meant to shift like this.

If we remove more obstacles from the game which are also used on
non-debug-levels, we can really run into problems when suddenly 50 signs have
wrong descriptions.


The current issue can be easily fixed manually, but I'd like to have it not
happening at all. :)

Please do a small test to see if your hypothesis is correct.

Go to a new level, add a few obstacles, add a few sign messages, save, copy the
ship file somewhere.
Open leveleditor, delete a few obstacles, save, compare the files, check if the
sign message was shifted ingame.

It's not about deleting obstacles from a level, it's about removing an entire
obstacle (ID) from the game how it seems.

I already did a small test in form of a bisect as explained in the message above.

before b288109dcbf7d6fb245175c35392d852006d0a4b, everything was fine
in b288109dcbf7d6fb245175c35392d852006d0a4b we removed one obstacle
after b288109dcbf7d6fb245175c35392d852006d0a4b we had the sign messages shifted
by one
then I did a1c0e65b670b0fc731b1076d84c71f01e9a07d18 which caused the sign
messages to be shifted by two, its still this way now.

It's not an obstacle but an obstacle type or obstacle spec. Don't misuse words.
Your commit messages were wrong.

Also, technically I would be surprised if your hypothesis was true, so please do
a small test to check if it is correct. Go to a new level, add a few obstacles,
add a few sign messages, save, copy the
ship file somewhere. Remove an obstacle type, save, compare the files, check if
the sign message was shifted ingame.

Ok.
Made a new local git branch
added level, added few walls, doors and signs
committed
added sign messages
committed
restarted game, sign messages were fine
removed all obstacles (but the signs) from the map, save, commit, sign messages
were fine
quit the game, started game, loaded map, sign messages were fine now

(did I do everything as you wanted now?)

Added new level, added some walls, doors and signs, added sign messages.

Read again - "Remove an obstacle type"

added new level, added a few obstacles to the map, added signs + messages

reverted:
commit 4e583c7b7d20221aab78e0e72c281f32eb7d81f1
Author: matthiaskrgr <matthias.krueger@famsik.de>
Date:   Tue May 1 10:46:29 2012 +0200

    obstacles: implement transformers by int-ua.

(which removes the obstacle type)
loaded the test-level (sign messages were ok), saved the map, there were no
changed to the mapfile.

b288109dcbf7d6fb245175c35392d852006d0a4b <- is there a way to represent these
commits as human-readable (iterative and 7 characters or less)?

Is this bug maybe related to #512 ? 



@Miles
git log  b288109dcbf7d6fb245175c35392d852006d0a4b --format="%h" | head -n1 
->
git show b288109 
works :)

"Is this bug maybe related to #512 ?"

Why #512.
It is related to #638, I'm quite sure.
And since #638 has been resolved, you can also close this ticket, imo.

oops yes,I ment that one.