Half a bridge

[lucaspiller]

In the latest nightly build (for Windows) I was making a scenario and noticed that half of the bridges had disapeared. I have no idea how to repeat this but when you try and remove them the game crashes.

Here is the crash log:

Code: Select all

*** OpenTTD Crash Report ***
Date: 2004-07-03 13:33:12
Build: ??? built on Fri Jul  2 20:00:21 2004
Exception C0000005 at 00443CC9
Registers:
 EAX: 0000A00F EBX: 0054635C ECX: 00011F0F EDX: 00000100
 ESI: 00000001 EDI: 80000000 EBP: 0012FB74 ESP: 0012FB50
 EIP: 00443CC9 EFLAGS: 00010206

Bytes at CS:EIP:
 8A 91 E0 21 60 00 80 E2 F0 80 FA 90 75 0E 8A 91 E0 21 5F 00 80 E2 E0 80

Stack trace: 
 0000A00F 00443D9C 0012FB70 80000000 FFFF0000 0040AF23 0054635C 00000001
 00000010 0012FB84 00443F88 0000A00F 00000000 0012FBB8 0040AF4D 0000A00F
 00000000 00405566 000000F0 00000A00 00000000 00000000 00000000 00000090
 0000A00F 000000F0 0012FBD4 004054D8 000000F0 00000A00 00000000 00000000
 00000000 0012FC14 0040AFDA 0000A00F 00000000 00000000 00000000 00000004
 00000AE0 000001D0 00000001 00000000 7FFC7B3E 000009E0 000384C1 000000F0
 01000000 0012FC4C 00405835 000001D0 00000AE0 00000001 00000A00 00000000
 00009E09 00000004 0000AE1D 0040AF50 0000AE1D 00000000 01000000 0012FC74
 004288E5 0000AE1D 00009E09 00000000 00421905 00B50064 00000000 77D54E1E
 00547CAC 0012FCA0 00419820 00547CAC 0012FC88 00000000 B034480E 000001DC
 00000AE4 0000AE1D 00009E09 00000004 0012FCF8 0041DAF3 03B7BCC1 00000000
 00000000 00000009 00415B4C 00000000 0041B447 77E7AD86 00000001 00000000
 003C03BE 00000200 00000000 02AA0178 03B7BCA3 00000178 000002B7 00000000
 00000000 00000000 0012FD14 004154CF 00000001 7FFDF000 C0000000 0012FFB0
 77FA88F0 77F53860 7FFDEC00 000000B7 77E7A479 000000B7 00000000 77E6F750
 C0000035 7FFDF000 77E7AD86 00000000 00000018 0000000C 0012FD00 00000040
 00000000 00000000 00100010 00142138 0000000C 7FFDEBF8 00000000 00000000
 00142138 FFFFFFFF 0012FD9C 0048A954 00000000 FFFFFFFF 00000000 0012FE98
 0041CA37 00000000 001423D1 77E60000 0012FDF2 00AF0178 00AF0758 00AF1B38
 00AF1330 77FC1774 77F5F70F 00AF1B38 00AF1330 0000FFFF 00000000 00AF01F8
 00000000 00AF0168 00000000 77ECD040 00006B39 00000000 00241FC0 77E813C8
 73490000 00AF1B30 00AF1328 61654672 65727574 73657250 00746E65 00AF1B30
 00AF0178 00000000 00000000 00000000 00000000 00140000 0012FD84 77F59BAA
 77F59BB3 77E7AD86 00020000 7FFDF000 00000088 00000808 77F5B2A0 7FFDF000

Module information:
 C:\Documents and Settings\Luca Spiller\Desktop\OTTD-win32-nightly_build\openttd.exe handle: 00400000 size: 590336 crc: B68CDECF date: 2004-07-02 19:01:56
 C:\WINDOWS\System32\ntdll.dll handle: 77F50000 size: 654336 crc: 137C90F3 date: 2003-05-01 15:56:12
 C:\WINDOWS\system32\kernel32.dll handle: 77E60000 size: 930304 crc: C9D88465 date: 2002-08-29 02:41:00
 C:\WINDOWS\System32\WINMM.dll handle: 76B40000 size: 171520 crc: CDB2A62A date: 2002-08-29 02:41:18
 C:\WINDOWS\system32\USER32.dll handle: 77D40000 size: 560128 crc: F6F0009F date: 2003-09-25 16:49:02
 C:\WINDOWS\system32\GDI32.dll handle: 7E090000 size: 257536 crc: C8DE69D8 date: 2004-03-30 01:48:36
 C:\WINDOWS\system32\ADVAPI32.dll handle: 77DD0000 size: 558080 crc: E8B5CA96 date: 2002-08-29 02:40:48
 C:\WINDOWS\system32\RPCRT4.dll handle: 78000000 size: 535552 crc: 9779ECD0 date: 2004-03-06 02:16:11
 C:\WINDOWS\System32\WS2_32.dll handle: 71AB0000 size: 75264 crc: 00979D06 date: 2001-08-18 11:00:00
 C:\WINDOWS\system32\msvcrt.dll handle: 77C10000 size: 323072 crc: 6B4C287C date: 2002-08-29 02:41:08
 C:\WINDOWS\System32\WS2HELP.dll handle: 71AA0000 size: 18944 crc: A104BC20 date: 2001-08-18 11:00:00
 C:\WINDOWS\System32\LPK.DLL handle: 629C0000 size: 18944 crc: 339805F0 date: 2001-08-18 11:00:00
 C:\WINDOWS\System32\USP10.dll handle: 72FA0000 size: 339456 crc: EEE0DBE8 date: 2002-08-29 02:41:18
 C:\WINDOWS\System32\wdmaud.drv handle: 72D20000 size: 22016 crc: 111175C9 date: 2001-08-18 11:00:00
 C:\WINDOWS\System32\msacm32.drv handle: 72D10000 size: 20480 crc: D5406BAE date: 2001-08-18 11:00:00
 C:\WINDOWS\System32\MSACM32.dll handle: 77BE0000 size: 67072 crc: 7C7B8D2A date: 2001-08-18 11:00:00
 C:\WINDOWS\System32\midimap.dll handle: 77BD0000 size: 17920 crc: 27FE86C2 date: 2001-08-18 11:00:00
 C:\WINDOWS\system32\ole32.dll handle: 771B0000 size: 1183744 crc: A00DF465 date: 2004-03-06 02:16:11
 C:\WINDOWS\System32\uxtheme.dll handle: 5AD70000 size: 203264 crc: 0F5145F0 date: 2002-08-29 02:41:18
 C:\Program Files\Messenger Plus! 3\MsgPlusH.dll handle: 10000000 size: 1269760 crc: BAD76C2A date: 2004-06-01 12:49:35
 C:\WINDOWS\system32\COMCTL32.dll handle: 77340000 size: 557056 crc: A7EC730F date: 2002-08-29 02:40:50
 C:\WINDOWS\system32\comdlg32.dll handle: 763B0000 size: 258048 crc: 02604FC3 date: 2002-08-29 02:40:50
 C:\WINDOWS\system32\SHLWAPI.dll handle: 70A70000 size: 395264 crc: 795B232E date: 2004-01-21 14:18:42
 C:\WINDOWS\system32\SHELL32.dll handle: 773D0000 size: 8240640 crc: D672E18A date: 2003-06-11 20:43:48
 C:\WINDOWS\system32\OLEAUT32.dll handle: 77120000 size: 569344 crc: D0AA7380 date: 2002-08-29 02:41:10
 C:\WINDOWS\WinSxS\x86_Microsoft.Windows.Common-Controls_6595b64144ccf1df_6.0.10.0_x-ww_f7fb5805\comctl32.dll handle: 71950000 size: 921600 crc: 48455D90 date: 2002-08-29 02:41:32
 C:\PROGRA~1\Grisoft\AVG6\avgoerun.dll handle: 00FE0000 size: 40960 crc: 53C6146A date: 2003-01-27 05:00:00
 C:\WINDOWS\System32\SynTPFcs.dll handle: 63000000 size: 65536 crc: 8F166CAE date: 2003-05-02 16:21:10
 C:\WINDOWS\system32\VERSION.dll handle: 77C00000 size: 16384 crc: 974DCE59 date: 2001-08-18 11:00:00
 C:\WINDOWS\System32\MSCTF.dll handle: 74720000 size: 266752 crc: 7830BEFF date: 2002-08-29 02:41:02
 C:\freeserve\freeserveconnectionkit\Freehook.dll handle: 01460000 size: 77824 crc: C4D4622C date: 2003-03-03 10:40:30
 C:\WINDOWS\System32\CLBCATQ.DLL handle: 7C890000 size: 499712 crc: 17CD2928 date: 2004-03-06 02:16:11
 C:\WINDOWS\System32\COMRes.dll handle: 77050000 size: 792064 crc: B9EC5C2F date: 2001-08-18 11:00:00
 C:\WINDOWS\System32\dmime.dll handle: 77300000 size: 171520 crc: 11D1A985 date: 2002-12-11 23:14:32
 C:\WINDOWS\System32\DSOUND.dll handle: 51080000 size: 355328 crc: 18E43175 date: 2002-12-11 23:14:32
 C:\WINDOWS\System32\dmusic.dll handle: 014C0000 size: 116736 crc: 845CD555 date: 2002-12-11 23:14:32
 C:\WINDOWS\System32\KsUser.dll handle: 5EF80000 size: 4096 crc: 853DEC10 date: 2002-12-11 23:14:32
 C:\WINDOWS\System32\dmsynth.dll handle: 01700000 size: 100864 crc: 8F12DF7F date: 2002-12-11 23:14:32
 C:\WINDOWS\System32\dmloader.dll handle: 01720000 size: 33280 crc: CED7D165 date: 2002-12-11 23:14:32
 C:\WINDOWS\System32\dmstyle.dll handle: 01730000 size: 98816 crc: F1BF6B2E date: 2002-12-11 23:14:32
 C:\WINDOWS\System32\dmband.dll handle: 01750000 size: 27136 crc: D295B557 date: 2002-12-11 23:14:32
 C:\WINDOWS\System32\mslbui.dll handle: 605D0000 size: 22528 crc: 5C30C4B7 date: 2002-08-29 02:41:06
 C:\WINDOWS\System32\psapi.dll handle: 76BF0000 size: 17408 crc: 6F4CD869 date: 2002-08-29 02:41:10

System information:
 Windows version 5.1 2600 Service Pack 1

[Darkvater]

lucaspiller it would be great if you would know how to repeat this. Because with your savegame, and screenshot, all we see are the consequences.

It could be fixed that the game doesn't crash when you try to remove the bridge, but the source of the problem won't be solved with that, so that 'workaround' is of no use.

[lucaspiller]

Ok, I will have a look and see if I can find out how.

[lucaspiller]

Ok, I think I have found what could be the cause.

When you click expand in the town screen of the scenario editor the and a bridge is built, if the end is blocked it will just build the first tile. If you remove this part it strangely clears a lot of the land around it too. If any bridges were here they would either be completely removed or partly removed. If you remove whatever is left of these bridges sometimes the game crashes.

[Darkvater]

Yes, thank you. Altough I have just found this bug completely independent of your findings (I was doing bridges on slopes), your observation is absolutely correct

The problem is the following:
With all commands, there is a testing phase first. Meaning that before any command is executed, it is checked if it can be executed. That's why you cannot build such bridges.
The problem with towns was that there was no such testphase, and execution was done immediately. Unfortunately the code was such, that first the bridge-start tile was checked, and if ok built. After that, the end tile was checked, and if ok, built. After that the middle section. If there is a test phase first, there is no problem, but without, only the start is built, then the game notices that an error has occured, and bails out. By that time, the start has already been built, and the damage done.