Freeze when finishing scenario

[Arcanister]

The bug seem to be reproducible with current wesnoth master and a week old build.

1. Install Mountain Witch addon campaign, or save won't work.
2. Load MoWi-Memory_of_the_Queen-Auto-Save37.gz
   (rename to .gz since github won't let upload .gz)
3. Move elf child into the island on top of the map
4. Click through dialogs
5. Wesnoth freezes

#0 std::__shared_ptr<config const, (__gnu_cxx::_Lock_policy)2>::__shared_ptr (this=0x7fffffff93a0) at /usr/include/c++/5.3.0/bits/shared_ptr_base.h:878
#1 0x000000000273125e in std::shared_ptr::shared_ptr (this=0x7fffffff93a0) at /usr/include/c++/5.3.0/bits/shared_ptr.h:105
#2 0x00000000031b4f4a in vconfig::vconfig (this=0x7fffffff93a0) at src/variable.cpp:72
#3 0x00000000031b50f6 in vconfig::unconstructed_vconfig () at src/variable.cpp:118
#4 0x000000000305ec1b in luaW_checkvconfig (L=0x7fffd61e46a8, index=1, allow_missing=false) src/scripting/lua_common.cpp:822
#5 0x000000000305cfbc in lua_common::impl_vconfig_ipairs_iter (L=0x7fffd61e46a8) at src/scripting/lua_common.cpp:331
#6 0x0000000003362c1c in luaD_precall (L=0x7fffd61e46a8, func=0x7fffd9786f20, nresults=2) at src/lua/ldo.cpp:365
#7 0x000000000337ef31 in luaV_execute (L=0x7fffd61e46a8) at src/lua/lvm.cpp:1134
#8 0x0000000003363268 in luaD_call (L=0x7fffd61e46a8, func=0x7fffd9786ef0, nResults=1) at src/lua/ldo.cpp:496
#9 0x000000000337f869 in luaV_execute (L=0x7fffd61e46a8) at src/lua/lvm.cpp:1248
#10 0x0000000003363268 in luaD_call (L=0x7fffd61e46a8, func=0x7fffd4c5a4e0, nResults=0) at src/lua/ldo.cpp:496
#11 0x00000000033632c6 in luaD_callnoyield (L=0x7fffd61e46a8, func=0x7fffd4c5a4e0, nResults=0) at src/lua/ldo.cpp:506
#12 0x000000000335a108 in f_call (L=0x7fffd61e46a8, ud=0x7fffffffa2b0) at src/lua/lapi.cpp:942
#13 0x0000000003362171 in luaD_rawrunprotected (L=0x7fffd61e46a8, f=0x335a0d3 <f_call(lua_State*, void*)>, ud=0x7fffffffa2b0) at lua/ldo.cpp:142
#14 0x0000000003363a75 in luaD_pcall (L=0x7fffd61e46a8, func=0x335a0d3 <f_call(lua_State*, void*)>, u=0x7fffffffa2b0,
old_top=32, ef=16) at src/lua/ldo.cpp:727
#15 0x000000000335a1d7 in lua_pcallk (L=0x7fffd61e46a8, nargs=1, nresults=0, errfunc=-3, ctx=0, k=0x0) at src/lua/lapi.cpp:968

[gfgtdf]

does the stacktrace end at entry 15? A longer strack trace could be helpful here,

Also a lua/wml stacktrace might be helpful, not sure how to get that in your case though.

[gfgtdf]

Also, what makes you think that this is an engine bug and not a bug in the addon (Mountain Witch ) ?

[Arcanister]

Even if there is a bug in add-on, the game interface should not freeze, it should still allow to click menu items for example.

Still freezes after 85b36d6 though

[gfgtdf]

Even if there is a bug in add-on, the game interface should not freeze, it should still allow to click menu items for example.

This would require a massive change to the engine (making wml code run in a seperate process/thread etc.) , which would probably create namy other bugs, as of currently codes like while true do end; will freeze the game and we have curently no plans to change that.

[CelticMinstrel]

This would require a massive change to the engine (making wml code run in a seperate process/thread etc.) , which would probably create namy other bugs, as of currently codes like while true do end; will freeze the game and we have curently no plans to change that.

I think this would be easier than you'd think (barring loops coded in Lua); simply call out to the UI manager from various places in the logic, just like the AI already does in order to allow you to quit while it's working. (If I recall correctly, the call from AI is in the attack analysis function.)

[Arcanister]

The second commit fixes the particular problem with scenario.