migration to 5.0 notes add

NOTES.md

@@ -1,6 +1,86 @@
 
 
+### migration to mt 5.0/5.2
 
+There are the issues Tignasse Verte mentionned: Adding `placer` in `register_functions.lua` 
+and replacing the two occourances of `nodeupdate` with `minetest.check_for_falling`.
+
+Other changes are necessary because I changed (and had to change) quite a lot 
+in `mg_villages` internally recently. If you want to get further with running 
+the game under newer versions of MT, replace the versions of `cottages`, `handle_schematics` 
+and `mg_villages` AdventureTest comes with with the newest versions.
+
+Then, remove the line `mg_villages.on_generated(minp,maxp,seed)` in 
+`adventuretest/register_functions.lua`. This may have an impact on quests the 
+old explorer is handling out, but if you ignore these for now, the world ought to be usable.
+
+Comment out the file/content of `mg/fill_chests.lua` for now as that requires 
+a few adjustments for filling the chests with the right content, and that's a bit 
+too much to write here in an inconvenient forum post.
+
+You won't see any villagers spawning because their spawn blocks are not placed. 
+My first attempts there ended in a severe overcrowding of villagers. Needs 
+finetuning/understanding what BrandonReese did to keep it balanced. But then, 
+this seems to be an open issue on Github as well...
+
+Mobs will likely not work very well. A lot changed regarding them. 
+They certainly could use an update as well - as could the goblins. I'm sure the witches 
+from the same modder would feel welcome in the AdventureTest universe, too.
+
+###### now the changes in fact:
+
+DFeniks wrote:
+2020-01-07 10:02:08: ERROR[Main]: ServerError: AsyncErr: Lua: finishGenRuntime error from mod 'default' in callback item_OnPlace(): ...enturetest/mods/adventuretest/register_functions.lua:101: attempt to index local 'placer' (a nil value)
+
+Reason on server-side :
+
+Here are the changes made on server-side, concerning item_OnPlace, for the 5.X.X :
+https://dev.minetest.net/Changelog,
+0.4.16 → 5.0.0 , Released March 4th 2019 / Server-side / User interface / Items
+
+Set placer to nil instead of a non-functional one in item_OnPlace (DTA7)
+Here is why, you may have a nil placer. One issue had been logged :
+https://github.com/minetest/minetest/issues/6487
+place_node crashes the game because of nil player #6487
+
+Here is the commit corresponding :
+https://github.com/minetest/minetest_game/pull/1907/commits/73c5339adb8ff93328f5439bf842767b71e0ce6c
+Add nil checks for placer #1907
+
+Reason in the mod :
+For Adventure Test, in `dungeons.lua`, you have line 33 a `minetest.register_on_generated()`, 
+in it, you have, line 161, a call of `minetest.place_node()`.
+
+In `register_functions.lua`, you have a `minetest.register_on_placenode(adventuretest_placenode)`, 
+so the call of `place_node()` redirect to `adventuretest_placenode()`.
+In the commit, I have found an example of change (a nil check) that can be done 
+in `adventuretest_placenode()`.
+
+What to do :
+Go to :
+games\adventuretest\mods\adventuretest
+There, change the file :
+`register_functions.lua` replace the line 101 (`if placer:is_player() then`) with :
+
+```
+if placer and placer:is_player() then
+```
+
+0.4.16 → 5.0.0 :
+`nodeupdate()` was removed. Fix: replace with `minetest.check_for_falling`.
+
+In Adventuretest I have found 2 calls of `nodeupdate()` (may be there is more).
+When it have been called, I got a crash :
+`AsyncErr: ServerThread::run Lua: Runtime error from mod 'default' in callback LuaABM::trigger(): ...32\bin\..\games\adventuretest\mods\default/functions.lua:385: attempt to call global 'nodeupdate' (a nil value)`
+
+What to do :
+Change the file
+`games\adventuretest\mods\default\functions.lua`
+replace the line 385 (nodeupdate(p0)) with :
+`minetest.check_for_falling(p0)`
+
+Then, change the file `games\adventuretest\mods\doors\init.lua` replace the line 374 with :
+`minetest.check_for_falling({x = pos.x, y = pos.y + 1, z = pos.z})`
 
 ### Fiel of view for monsters vs characters