SCI: Script patch for critical Colonel's Bequest game bug

This patch is about an issue, when interacting with the
armor in room 37 (main house, downstairs).

This bug also happened, when using the original interpreter
and effectively froze the game depending on the coordinate
of Laura Bow, when the command was entered.

Fixes bug #7119

Versions affected: English PC/Atari ST/Amiga Floppy

1 files changed, 64 insertions, 1 deletions

diff --git a/engines/sci/engine/script_patches.cpp b/engines/sci/engine/script_patches.cpp
index 0280912c6b..b1603266d8 100644
--- a/engines/sci/engine/script_patches.cpp
+++ b/engines/sci/engine/script_patches.cpp
@@ -1654,9 +1654,72 @@ static const uint16 laurabow1PatchEasterEggViewFix[] = {
 	PATCH_END
 };
 
+// When oiling the armor or opening the visor of the armor, the scripts
+//  first check if Laura/ego is near the armor and if she is not, they will move her
+//  to the armor. After that further code is executed.
+//
+// The current location is checked by a ego::inRect() call.
+//
+// The given rect for the inRect call inside openVisor::changeState was made larger for Atari ST/Amiga versions.
+//  We change the PC version to use the same rect.
+//
+// Additionally the coordinate, that Laura is moved to, is 152, 107 and may not be reachable depending on where
+//  Laura/ego was, when "use oil on helmet of armor" / "open visor of armor" got entered.
+//  Bad coordinates are for example 82, 110, which then cause collisions and effectively an endless loop.
+//  Game will effectively "freeze" and the user is only able to restore a previous game.
+//  This also happened, when using the original interpreter.
+//  We change the destination coordinate to 152, 110, which seems to be reachable all the time.
+//
+// The following patch fixes the rect for the PC version of the game.
+//
+// Applies to at least: English PC Floppy
+// Responsible method: openVisor::changeState (script 37)
+// Fixes bug: #7119
+static const uint16 laurabow1SignatureArmorOpenVisorFix[] = {
+	0x39, 0x04,                         // pushi 04
+	SIG_MAGICDWORD,
+	0x39, 0x6a,                         // pushi 6a (106d)
+	0x38, SIG_UINT16(0x96),             // pushi 0096 (150d)
+	0x39, 0x6c,                         // pushi 6c (108d)
+	0x38, SIG_UINT16(0x98),             // pushi 0098 (152d)
+	SIG_END
+};
+
+static const uint16 laurabow1PatchArmorOpenVisorFix[] = {
+	PATCH_ADDTOOFFSET(+2),
+	0x39, 0x68,                         // pushi 68 (104d)   (-2)
+	0x38, SIG_UINT16(0x94),             // pushi 0094 (148d) (-2)
+	0x39, 0x6f,                         // pushi 6f (111d)   (+3)
+	0x38, SIG_UINT16(0x9a),             // pushi 009a (154d) (+2)
+	PATCH_END
+};
+
+// This here fixes the destination coordinate (exact details are above).
+//
+// Applies to at least: English PC Floppy, English Atari ST Floppy, English Amiga Floppy
+// Responsible method: openVisor::changeState, oiling::changeState (script 37)
+// Fixes bug: #7119
+static const uint16 laurabow1SignatureArmorMoveToFix[] = {
+	SIG_MAGICDWORD,
+	0x36,                               // push
+	0x39, 0x6b,                         // pushi 6B (107d)
+	0x38, SIG_UINT16(0x0098),           // pushi 98 (152d)
+	0x7c,                               // pushSelf
+	0x81, 0x00,                         // lag global[0]
+	SIG_END
+};
+
+static const uint16 laurabow1PatchArmorMoveToFix[] = {
+	PATCH_ADDTOOFFSET(+1),
+	0x39, 0x6e,                         // pushi 6E (110d) - adjust x, so that no collision can occur anymore
+	PATCH_END
+};
+
 //          script, description,                                      signature                           patch
 static const SciScriptPatcherEntry laurabow1Signatures[] = {
-	{  true,     4, "easter egg view fix",                         1, laurabow1SignatureEasterEggViewFix, laurabow1PatchEasterEggViewFix },
+	{  true,     4, "easter egg view fix",                         1, laurabow1SignatureEasterEggViewFix,  laurabow1PatchEasterEggViewFix },
+	{  true,    37, "armor open visor fix",                        1, laurabow1SignatureArmorOpenVisorFix, laurabow1PatchArmorOpenVisorFix },
+	{  true,    37, "armor move to fix",                           2, laurabow1SignatureArmorMoveToFix,    laurabow1PatchArmorMoveToFix },
 	SCI_SIGNATUREENTRY_TERMINATOR
 };