GOB2: Seg fault when trying to switch screen in music land

savegame in music world

Logged In: YES
user_id=1682513
Originator: YES

Got it working in dosbox, and hen you click on the "MOVEMENT" icon in music world, nothing happens at all (nothing pops up)

Logged In: YES
user_id=1682513
Originator: YES

I suspect this is related, so I'll put it here as well. Let me know if you'd like a separate report. Told you I'd find more bugs ;-)

Having finished music land (at last!), when clicking the MOVEMENT icon, nothing happens. In the original interpreter, this shows the one other place that it's possible to go (the trench). The same thing happens at the trench (but the other way round).

Logged In: YES
user_id=556976
Originator: NO

Could you try and look whether my attempted fix for #1706988 chances anything for this bug(s) as well? You'd have to start with a save from before musicland, though.

Logged In: YES
user_id=1682513
Originator: YES

No, fraid not. Still the same problem with revision 26727.

Logged In: YES
user_id=166507
Originator: NO

(gdb) thread 4
[Switching to thread 4 (Thread 0x8187000 (runnable))]#0 0x28c6f6e6 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0', j=9 '\t',
params=@0xbfbfd66c) at engines/gob/inter_v2.cpp:680
680 return (this->*op) (params);
(gdb) bt
#0 0x28c6f6e6 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0',
j=9 '\t', params=@0xbfbfd66c) at engines/gob/inter_v2.cpp:680
#1 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=1)
at engines/gob/inter.cpp:242
#2 0x28c67034 in Gob::Inter_v1::o1_repeatUntil (this=0x82fbc00,
params=@0xbfbfd70c) at engines/gob/inter_v1.cpp:1230
#3 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0',
j=6 '\006', params=@0xbfbfd70c) at engines/gob/inter_v2.cpp:680
#4 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:242
#5 0x28c64665 in Gob::Inter::callSub (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:270
#6 0x28c66c1c in Gob::Inter_v1::o1_callSub (this=0x82fbc00,
params=@0xbfbfd7cc) at engines/gob/inter_v1.cpp:1154
#7 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0',
j=0 '\0', params=@0xbfbfd7cc) at engines/gob/inter_v2.cpp:680
#8 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=0)
at engines/gob/inter.cpp:242
#9 0x28c672f0 in Gob::Inter_v1::o1_if (this=0x82fbc00, params=@0xbfbfd86c)
at engines/gob/inter_v1.cpp:1294
#10 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0',
j=8 '\b', params=@0xbfbfd86c) at engines/gob/inter_v2.cpp:680
#11 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:242
#12 0x28c64665 in Gob::Inter::callSub (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:270
#13 0x28c476d5 in Gob::Game_v2::playTot (this=0x8291000, skipPlay=4)
at engines/gob/game_v2.cpp:282
#14 0x28c3fb8e in Gob::Game::switchTotSub (this=0x8291000, index=0, skipPlay=4)
at engines/gob/game.cpp:580
#15 0x28c7179c in Gob::Inter_v2::o2_switchTotSub (this=0x82fbc00)
at engines/gob/inter_v2.cpp:1146
#16 0x28c6f5b2 in Gob::Inter_v2::executeDrawOpcode (this=0x82fbc00, i=65 'A')
at engines/gob/inter_v2.cpp:663
#17 0x28c68f09 in Gob::Inter_v1::o1_drawOperations (this=0x82fbc00,
params=@0xbfbfda8c) at engines/gob/inter_v1.cpp:1719
#18 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00,
i=1 '\001', j=14 '\016', params=@0xbfbfda8c)
at engines/gob/inter_v2.cpp:680
#19 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=0)
at engines/gob/inter.cpp:242
#20 0x28c672f0 in Gob::Inter_v1::o1_if (this=0x82fbc00, params=@0xbfbfdb2c)
at engines/gob/inter_v1.cpp:1294
#21 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0',
j=8 '\b', params=@0xbfbfdb2c) at engines/gob/inter_v2.cpp:680
#22 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=0)
at engines/gob/inter.cpp:242
#23 0x28c403c2 in Gob::Game::collSub (this=0x8291000, offset=12419)
---Type <return> to continue, or q <return> to quit---
at engines/gob/game.cpp:726
#24 0x28c40554 in Gob::Game::collAreaSub (this=0x8291000, index=2,
enter=1 '\001') at engines/gob/game.cpp:750
#25 0x28c484a3 in Gob::Game_v2::checkCollisions (this=0x8291000,
handleMouse=1 '\001', deltaTime=-2, pResId=0x829170e, pResIndex=0x8291710)
at engines/gob/game_v2.cpp:529
#26 0x28c4a123 in Gob::Game_v2::collisionsBlock (this=0x8291000)
at engines/gob/game_v2.cpp:899
#27 0x28c6469d in Gob::Inter::callSub (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:272
#28 0x28c66c1c in Gob::Inter_v1::o1_callSub (this=0x82fbc00,
params=@0xbfbfe00c) at engines/gob/inter_v1.cpp:1154
#29 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0',
j=1 '\001', params=@0xbfbfe00c) at engines/gob/inter_v2.cpp:680
#30 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=1)
at engines/gob/inter.cpp:242
#31 0x28c67034 in Gob::Inter_v1::o1_repeatUntil (this=0x82fbc00,
params=@0xbfbfe0ac) at engines/gob/inter_v1.cpp:1230
#32 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0',
j=6 '\006', params=@0xbfbfe0ac) at engines/gob/inter_v2.cpp:680
#33 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:242
#34 0x28c64665 in Gob::Inter::callSub (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:270
#35 0x28c4730f in Gob::Game_v2::playTot (this=0x8291000, skipPlay=-1)
at engines/gob/game_v2.cpp:219
#36 0x28c3f462 in Gob::Game::totSub (this=0x8291000, flags=2 '\002',
newTotFile=0xbfbfe210 "gob06") at engines/gob/game.cpp:501
#37 0x28c7173b in Gob::Inter_v2::o2_totSub (this=0x82fbc00)
at engines/gob/inter_v2.cpp:1136
#38 0x28c6f5b2 in Gob::Inter_v2::executeDrawOpcode (this=0x82fbc00, i=64 '@')
at engines/gob/inter_v2.cpp:663
#39 0x28c68f09 in Gob::Inter_v1::o1_drawOperations (this=0x82fbc00,
params=@0xbfbfe2ec) at engines/gob/inter_v1.cpp:1719
#40 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00,
i=1 '\001', j=14 '\016', params=@0xbfbfe2ec)
at engines/gob/inter_v2.cpp:680
#41 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=1)
at engines/gob/inter.cpp:242
#42 0x28c67034 in Gob::Inter_v1::o1_repeatUntil (this=0x82fbc00,
params=@0xbfbfe38c) at engines/gob/inter_v1.cpp:1230
#43 0x28c6f6e3 in Gob::Inter_v2::executeFuncOpcode (this=0x82fbc00, i=0 '\0',
j=6 '\006', params=@0xbfbfe38c) at engines/gob/inter_v2.cpp:680
#44 0x28c64549 in Gob::Inter::funcBlock (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:242
#45 0x28c64665 in Gob::Inter::callSub (this=0x82fbc00, retFlag=2)
at engines/gob/inter.cpp:270
#46 0x28c4730f in Gob::Game_v2::playTot (this=0x8291000, skipPlay=0)
at engines/gob/game_v2.cpp:219
#47 0x28c3f113 in Gob::Game::start (this=0x8291000) at engines/gob/game.cpp:451
#48 0x28c62ef6 in Gob::Init::initGame (this=0x82673a0, totName=0x0)
at engines/gob/init.cpp:192
#49 0x28c4ece2 in Gob::GobEngine::go (this=0x827d400)
at engines/gob/gob.cpp:119
#50 0x0808c572 in runGame (plugin=0x827d800, system=@0x818a000,
edebuglevels=@0xbfbfe850) at base/main.cpp:202
#51 0x0808cc57 in scummvm_main (argc=4, argv=0xbfbfe928) at base/main.cpp:297
#52 0x08089bc4 in main (argc=4, argv=0xbfbfe928)
at backends/platform/sdl/sdl.cpp:121

Logged In: YES
user_id=166507
Originator: NO

Raising priority. This is a release-critical bug.

Logged In: YES
user_id=556976
Originator: NO

Could you give me a save from a point right before entering music land?

savegame from just before music land

Logged In: YES
user_id=1682513
Originator: YES

File Added: gob2cd.s14

Logged In: YES
user_id=556976
Originator: NO

Hmm, three things I found out (after a futile wild goose chase):
1) There are versions that behave correctly and versions that don't
2) The bug happens a bit before. When one goblin drinks the fluid, var_4344 should be decreased by 32 (var_4344 is used to "mask out" the unselectable buttons and the fifth bit is the MOVEMENT button) but isn't
3) Incorrectly behaving versions behave incorrectly in dosbox as well. The "var_4344 = var_4344 - 32" line is literally missing in the scripts of these versions.

So it's a script bug and I can't really fix it. :/
The only thing I can do (and did) is to add a workaround. You'll get a "I confirm" dialog when trying to use the MOVEMENT menu now, but that shouldn't create any problems.

Could you try if it works for you too?

Logged In: YES
user_id=1682513
Originator: YES

Hmmm, very odd. I will check this when I get home, and I'll also re-check dosbox behaviour. I'm sure that running my version (from the 2CD gob1&2 sierra double pack) in dosbox doesn't crash, and in scummvm does. I'll make absolutely sure I'm using the same files in both (tho I only have the one copy of gob2!). If there's something I can try out, even if it involves gdb (shivers), let me know.

Logged In: YES
user_id=1682513
Originator: YES

Yes, your workaround works (stops the seg fault). It doesn't affect the MOVEMENT icon not working after musicland, as mentioned in my second comment to this bug.

Re-checked dosbox, and my version works correctly there: maybe they added a workaround when they re-released it? The MOVEMENT icon doesn't even highlight there.

Logged In: YES
user_id=12935
Originator: NO

Since a workaround is in place, could we lower the priority from "release critical" to "would be nice to fix" again?

Logged In: YES
user_id=1682513
Originator: YES

From my pov yes. I don't know what drmccoy's progress with this has been, but it doesn't segfault anymore so it's releasable.

Logged In: YES
user_id=166507
Originator: NO

Lowering priority,

Logged In: YES
user_id=166507
Originator: NO

Sven, do you think we may just close this bugreport?

Logged In: YES
user_id=556976
Originator: NO

Well, there's a workaround, but it's not "properly" fixed... I'll lower the priority.

Was there a discussion that led to this being marked "Also occurs in the original"? Because it didn't when I tried it (which admittedly was over a year ago now).

OK, I've reverted this from "Also occurs in the original".
As I understand it, and it's over a year since I investigated so I'm willing to be corrected:
On the tree screen, after completing music world:
The MOVEMENT icon on the drop-down toolbar does not do anything in ScummVM. In the original game, it allows you to choose the only other place available, the castle.
(IIRC, the behaviour of ScummVM differed from original interpreter in music land too, but the above is the better and more obvious example).
I'll attach a savegame at the place described above too.