SCI: Fix SCI3 exports

Export functions may be relocated above 64k in SCI3, but exports that do not have an entry in the relocation table must be handled the same as SCI1.1-2.1.
scummvm · Apr 23, 2017 · a799cb3 · a799cb3
1 parent fc02b34
commit a799cb3
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Showing 4 changed files with 19 additions and 11 deletions.
diff --git a/engines/sci/engine/guest_additions.cpp b/engines/sci/engine/guest_additions.cpp
@@ -397,7 +397,7 @@ static const byte SRTorinPatch[] = {
 };
 
 void GuestAdditions::patchGameSaveRestoreTorin(Script &script) const {
-	const uint16 address = script.validateExportFunc(2, true);
+	const uint32 address = script.validateExportFunc(2, true);
 	byte *patchPtr = const_cast<byte *>(script.getBuf(address));
 	memcpy(patchPtr, SRTorinPatch, sizeof(SRTorinPatch));
 	if (g_sci->isBE()) {

diff --git a/engines/sci/engine/kscripts.cpp b/engines/sci/engine/kscripts.cpp
@@ -246,7 +246,7 @@ reg_t kScriptID(EngineState *s, int argc, reg_t *argv) {
 		return NULL_REG;
 	}
 
-	uint16 address = scr->validateExportFunc(index, true);
+	uint32 address = scr->validateExportFunc(index, true);
 
 	// Point to the heap for SCI1.1 - SCI2.1 games
 	if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1_LATE)

diff --git a/engines/sci/engine/script.cpp b/engines/sci/engine/script.cpp
@@ -505,6 +505,7 @@ void Script::identifyOffsets() {
 		if (_buf->size() < 22)
 			error("Script::identifyOffsets(): script %d smaller than expected SCI3-header", _nr);
 
+		_codeOffset = _buf->getUint32LEAt(0);
 		sci3StringOffset = _buf->getUint32LEAt(4);
 		sci3RelocationOffset = _buf->getUint32LEAt(8);
 
@@ -796,23 +797,29 @@ uint32 Script::validateExportFunc(int pubfunct, bool relocSci3) {
 	if (exportsAreWide)
 		pubfunct *= 2;
 
-	uint32 offset;
+	int offset;
 
 	if (getSciVersion() != SCI_VERSION_3) {
 		offset = _exports.getUint16SEAt(pubfunct);
 	} else {
-		if (!relocSci3)
-			offset = _exports.getUint16SEAt(pubfunct) + getCodeBlockOffsetSci3();
-		else
-			offset = relocateOffsetSci3(pubfunct * 2 + 22);
+		if (!relocSci3) {
+			offset = _exports.getUint16SEAt(pubfunct) + getCodeBlockOffset();
+		} else {
+			offset = relocateOffsetSci3(pubfunct * sizeof(uint16) + /* header size */ 22);
+			// Some offsets below 0xFFFF are left as-is in the export table,
+			// e.g. Lighthouse script 64990
+			if (offset == -1) {
+				offset = _exports.getUint16SEAt(pubfunct) + getCodeBlockOffset();
+			}
+		}
 	}
 
 	// TODO: Check if this should be done for SCI1.1 games as well
 	if (getSciVersion() >= SCI_VERSION_2 && offset == 0) {
-		offset = _codeOffset;
+		offset = getCodeBlockOffset();
 	}
 
-	if (offset >= _buf->size())
+	if (offset == -1 || offset >= (int)_buf->size())
 		error("Invalid export function pointer");
 
 	return offset;

diff --git a/engines/sci/engine/script.h b/engines/sci/engine/script.h
@@ -260,9 +260,10 @@ class Script : public SegmentObj {
 	int relocateOffsetSci3(uint32 offset) const;
 
 	/**
-	 * Gets an offset to the beginning of the code block in a SCI3 script
+	 * Gets an offset to the beginning of the code block in a SCI1.1 or later
+	 * script
 	 */
-	int getCodeBlockOffsetSci3() { return _buf->getInt32SEAt(0); }
+	int getCodeBlockOffset() { return _codeOffset; }
 
 	/**
 	 * Get the offset array