Crash when viewing AI textfile and switching to Random AI

[SamuXarick]

An example
AIAI version 97 has a changelog.txt

Steps:

• launch openttd
• click AI/GS Settings
• click Select AI
• select AIAI and click Accept
• click Changelog
• without closing Changelog, and without selecting another slot
• click Select AI
• select Random AI and click Accept

Crash!

[SamuXarick]

crash.zip

[LordAro]

Found the cause of the issue:

OpenTTD/src/ai/ai_gui.cpp

Line 175 in ed325ad

GetConfig(slot)->Change(NULL);

sets the slot to "null" (except that it's not actually NULL - see script_config.cpp)

Which is followed by getting the name of the "null" slot:

OpenTTD/src/ai/ai_gui.cpp

Line 645 in ed325ad

SetDParamStr(1, GetConfig(slot)->GetName());

[stale]

This issue has been automatically marked as stale because it has not had any activity in the last two months.
If you believe the issue is still relevant, please test on the latest nightly and report back.
It will be closed if no further activity occurs within 7 days.
Thank you for your contributions.

[SamuXarick]

Still crashes

openttd.exe!Utf8Decode(unsigned int * c, const char * s) Line 452 C++
openttd.exe!Utf8Consume(const char * * s) Line 90 C++
openttd.exe!FormatString(char * buff, const char * str_arg, StringParameters * args, const char * last, unsigned int case_index, bool game_script, bool dry_run) Line 796 C++
openttd.exe!FormatString(char * buff, const char * str_arg, StringParameters * args, const char * last, unsigned int case_index, bool game_script, bool dry_run) Line 787 C++
openttd.exe!FormatString(char * buff, const char * str_arg, StringParameters * args, const char * last, unsigned int case_index, bool game_script, bool dry_run) Line 1006 C++
openttd.exe!FormatString(char * buff, const char * str_arg, StringParameters * args, const char * last, unsigned int case_index, bool game_script, bool dry_run) Line 787 C++
openttd.exe!GetStringWithArgs(char * buffr, unsigned int string, StringParameters * args, const char * last, unsigned int case_index, bool game_script) Line 262 C++
openttd.exe!GetString(char * buffr, unsigned int string, const char * last) Line 269 C++
openttd.exe!GetStringBoundingBox(unsigned int strid) Line 715 C++
openttd.exe!DrawCaption(const Rect & r, Colours colour, Owner owner, unsigned int str) Line 552 C++
openttd.exe!NWidgetLeaf::Draw(const Window * w) Line 2474 C++
openttd.exe!NWidgetPIPContainer::Draw(const Window * w) Line 1114 C++
openttd.exe!NWidgetPIPContainer::Draw(const Window * w) Line 1114 C++
openttd.exe!Window::DrawWidgets() Line 608 C++
openttd.exe!Window::OnPaint() Line 563 C++
openttd.exe!DrawOverlappedWindow(Window * w, int left, int top, int right, int bottom) Line 933 C++
openttd.exe!DrawOverlappedWindowForAll(int left, int top, int right, int bottom) Line 960 C++
openttd.exe!RedrawScreenRect(int left, int top, int right, int bottom) Line 1293 C++
openttd.exe!DrawDirtyBlocks() Line 1391 C++
openttd.exe!UpdateWindows() Line 3185 C++
openttd.exe!VideoDriver_Win32::MainLoop() Line 1280 C++
openttd.exe!openttd_main(int argc, char * * argv) Line 849 C++
openttd.exe!WinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, char * lpCmdLine, int nCmdShow) Line 443 C++
[External Code]
Exception thrown: read access violation.
s was nullptr.

tested on OpenTTD 2019-03-22-master-gd755375966

[James103]

Still crashes in OpenTTD 1.10.0-beta1. Crash files have been attached (including .log, .png, .dmp, and .sav).