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SCI32: Fix QFG4 copy protection crash, bug #10773 (#1431)

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sluicebox authored and bluegr committed Dec 3, 2018
1 parent c22e8eb commit b9c60558369f0c503e82ba029eb5c78583dc3e6b
Showing with 41 additions and 0 deletions.
  1. +41 −0 engines/sci/engine/script_patches.cpp
@@ -8288,6 +8288,46 @@ static const uint16 qfg4ConditionalVoidPatch[] = {
PATCH_END
};
// The copy protection in floppy versions has a script bug which uses disposed
// objects and crashes our interpreter. This appears to work in Sierra's
// interpreter although they fixed the script bug in the CD version.
//
// When asking Dr. Cranium in room 370 about certain potions the game switches
// to a copy protection screen and then back to the conversation. Before the
// switch, craniumTalker is disposed, which in turn disposes craniumThumbs and
// craniumBrow. Disposing these views clears their planes. After returning from
// the protection screen craniumTalker:showAgain is called even though it has
// been disposed. This causes kAddScreenItem to be called on views without
// planes, which is currently an error in our interpreter.
//
// We work around this by reinitializing craniumTalker after the copy protection
// so that showAgain can be safely called. craniumTalker is reinitialized when
// navigating through the conversation menus so this is normal behavior.
//
// Applies to: English PC Floppy, German PC Floppy
// Responsible method: delayMsg:changeState(0)
// Fixes bug: #10773
static const uint16 qfg4CopyProtectionSignature[] = {
0x31, 0x06, // bnt 06
SIG_MAGICDWORD,
0x35, 0x01, // ldi 01
0x65, 0x24, // aTop register
SIG_ADDTOOFFSET(+6),
0x38, SIG_UINT16(0x0300), // pushi 0300 [ showAgain, hard-coded for floppy ]
SIG_ADDTOOFFSET(+11),
0x4a, SIG_UINT16(0x0004), // send 04 [ craniumTalker: showAgain ]
SIG_END
};
static const uint16 qfg4CopyProtectionPatch[] = {
0x65, 0x24, // aTop register
0x38, PATCH_SELECTOR16(init), // pushi init
0x76, // push0
PATCH_ADDTOOFFSET(+20),
0x4a, PATCH_UINT16(0x0008), // send 08 [ craniumTalker: init, showAgain ]
PATCH_END
};
// script, description, signature patch
static const SciScriptPatcherEntry qfg4Signatures[] = {
{ true, 0, "prevent autosave from deleting save games", 1, qg4AutosaveSignature, qg4AutosavePatch },
@@ -8301,6 +8341,7 @@ static const SciScriptPatcherEntry qfg4Signatures[] = {
{ true, 83, "fix incorrect array type (floppy)", 1, qfg4TrapArrayTypeFloppySignature, qfg4TrapArrayTypeFloppyPatch },
{ true, 320, "fix pathfinding at the inn", 1, qg4InnPathfindingSignature, qg4InnPathfindingPatch },
{ true, 320, "fix talking to absent innkeeper", 1, qfg4AbsentInnkeeperSignature, qfg4AbsentInnkeeperPatch },
{ true, 370, "Floppy: fix copy protection", 1, qfg4CopyProtectionSignature, qfg4CopyProtectionPatch },
{ true, 440, "fix setLooper calls (1/2)", 1, qg4SetLooperSignature1, qg4SetLooperPatch1 },
{ true, 470, "fix Magda room disposal", 1, qfg4MagdaDisposalSignature, qfg4MagdaDisposalPatch },
{ true, 530, "fix setLooper calls (1/2)", 4, qg4SetLooperSignature1, qg4SetLooperPatch1 },

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