5 files changed, 46 insertions, 16 deletions

diff --git a/engines/sci/engine/kernel.cpp b/engines/sci/engine/kernel.cpp
index 796dea2382..4370e6de04 100644
--- a/engines/sci/engine/kernel.cpp
+++ b/engines/sci/engine/kernel.cpp
@@ -91,6 +91,20 @@ const Common::String &Kernel::getKernelName(uint number) const {
 	return _kernelNames[number];
 }
 
+Common::String Kernel::getKernelName(uint number, uint subFunction) const {
+	// FIXME: The following check is a temporary workaround for an issue
+	// leading to crashes when using the debugger's backtrace command.
+	if (number >= _kernelFuncs.size())
+		return _invalid;
+	const KernelFunction &kernelCall = _kernelFuncs[number];
+
+	if (subFunction >= kernelCall.subFunctionCount)
+		return _invalid;
+
+	return kernelCall.subFunctions[subFunction].name;
+}
+
+
 int Kernel::findKernelFuncPos(Common::String kernelFuncName) {
 	for (uint32 i = 0; i < _kernelNames.size(); i++)
 		if (_kernelNames[i] == kernelFuncName)
diff --git a/engines/sci/engine/kernel.h b/engines/sci/engine/kernel.h
index 1202982986..d95e228045 100644
--- a/engines/sci/engine/kernel.h
+++ b/engines/sci/engine/kernel.h
@@ -158,6 +158,7 @@ public:
 
 	uint getKernelNamesSize() const;
 	const Common::String &getKernelName(uint number) const;
+	Common::String getKernelName(uint number, uint subFunction) const;
 
 	/**
 	 * Determines the selector ID of a selector by its name.
diff --git a/engines/sci/engine/kmisc.cpp b/engines/sci/engine/kmisc.cpp
index 0a5f26476f..065625f85f 100644
--- a/engines/sci/engine/kmisc.cpp
+++ b/engines/sci/engine/kmisc.cpp
@@ -605,18 +605,28 @@ reg_t kEmpty(EngineState *s, int argc, reg_t *argv) {
 reg_t kStub(EngineState *s, int argc, reg_t *argv) {
 	Kernel *kernel = g_sci->getKernel();
 	int kernelCallNr = -1;
+	int kernelSubCallNr = -1;
 
 	Common::List<ExecStack>::const_iterator callIterator = s->_executionStack.end();
 	if (callIterator != s->_executionStack.begin()) {
 		callIterator--;
 		ExecStack lastCall = *callIterator;
-		kernelCallNr = lastCall.debugSelector;
+		kernelCallNr = lastCall.debugKernelFunction;
+		kernelSubCallNr = lastCall.debugKernelSubFunction;
 	}
 
-	Common::String warningMsg = "Dummy function k" + kernel->getKernelName(kernelCallNr) +
-								Common::String::format("[%x]", kernelCallNr) +
-								" invoked. Params: " +
-								Common::String::format("%d", argc) + " (";
+	Common::String warningMsg;
+	if (kernelSubCallNr == -1) {
+		warningMsg = "Dummy function k" + kernel->getKernelName(kernelCallNr) +
+		             Common::String::format("[%x]", kernelCallNr);
+	} else {
+		warningMsg = "Dummy function k" + kernel->getKernelName(kernelCallNr, kernelSubCallNr) +
+		             Common::String::format("[%x:%x]", kernelCallNr, kernelSubCallNr);
+
+	}
+
+	warningMsg += " invoked. Params: " +
+	              Common::String::format("%d", argc) + " (";
 
 	for (int i = 0; i < argc; i++) {
 		warningMsg +=  Common::String::format("%04x:%04x", PRINT_REG(argv[i]));
diff --git a/engines/sci/engine/vm.cpp b/engines/sci/engine/vm.cpp
index 64e6c045db..7e708efc8b 100644
--- a/engines/sci/engine/vm.cpp
+++ b/engines/sci/engine/vm.cpp
@@ -240,7 +240,7 @@ ExecStack *execute_method(EngineState *s, uint16 script, uint16 pubfunct, StackP
 	g_sci->checkExportBreakpoint(script, pubfunct);
 
 	ExecStack xstack(calling_obj, calling_obj, sp, argc, argp,
-						seg, make_reg32(seg, exportAddr), -1, pubfunct, -1,
+						seg, make_reg32(seg, exportAddr), -1, -1, -1, pubfunct, -1,
 						s->_executionStack.size() - 1, EXEC_STACK_TYPE_CALL);
 	s->_executionStack.push_back(xstack);
 	return &(s->_executionStack.back());
@@ -313,7 +313,7 @@ ExecStack *send_selector(EngineState *s, reg_t send_obj, reg_t work_obj, StackPt
 			debugSelectorCall(send_obj, selector, argc, argp, varp, funcp, s->_segMan, selectorType);
 
 		ExecStack xstack(work_obj, send_obj, curSP, argc, argp,
-							0xFFFF, curFP, selector, -1, -1,
+							0xFFFF, curFP, selector, -1, -1, -1, -1,
 							origin, stackType);
 
 		if (selectorType == kSelectorVariable)
@@ -335,12 +335,12 @@ ExecStack *send_selector(EngineState *s, reg_t send_obj, reg_t work_obj, StackPt
 	return s->_executionStack.empty() ? NULL : &(s->_executionStack.back());
 }
 
-static void addKernelCallToExecStack(EngineState *s, int kernelCallNr, int argc, reg_t *argv) {
+static void addKernelCallToExecStack(EngineState *s, int kernelCallNr, int kernelSubCallNr, int argc, reg_t *argv) {
 	// Add stack frame to indicate we're executing a callk.
 	// This is useful in debugger backtraces if this
 	// kernel function calls a script itself.
 	ExecStack xstack(NULL_REG, NULL_REG, NULL, argc, argv - 1, 0xFFFF, make_reg32(0, 0),
-						kernelCallNr, -1, -1, s->_executionStack.size() - 1, EXEC_STACK_TYPE_KERNEL);
+						-1, kernelCallNr, kernelSubCallNr, -1, -1, s->_executionStack.size() - 1, EXEC_STACK_TYPE_KERNEL);
 	s->_executionStack.push_back(xstack);
 }
 
@@ -386,7 +386,7 @@ static void callKernelFunc(EngineState *s, int kernelCallNr, int argc) {
 
 	// Call kernel function
 	if (!kernelCall.subFunctionCount) {
-		addKernelCallToExecStack(s, kernelCallNr, argc, argv);
+		addKernelCallToExecStack(s, kernelCallNr, -1, argc, argv);
 		s->r_acc = kernelCall.function(s, argc, argv);
 
 		if (kernelCall.debugLogging)
@@ -444,7 +444,7 @@ static void callKernelFunc(EngineState *s, int kernelCallNr, int argc) {
 		}
 		if (!kernelSubCall.function)
 			error("[VM] k%s: subfunction ID %d requested, but not available", kernelCall.name, subId);
-		addKernelCallToExecStack(s, kernelCallNr, argc, argv);
+		addKernelCallToExecStack(s, kernelCallNr, subId, argc, argv);
 		s->r_acc = kernelSubCall.function(s, argc, argv);
 
 		if (kernelSubCall.debugLogging)
@@ -841,7 +841,7 @@ void run_vm(EngineState *s) {
 			ExecStack xstack(s->xs->objp, s->xs->objp, s->xs->sp,
 							(call_base->requireUint16()) + s->r_rest, call_base,
 							s->xs->local_segment, make_reg32(s->xs->addr.pc.getSegment(), localCallOffset),
-							NULL_SELECTOR, -1, localCallOffset, s->_executionStack.size() - 1,
+							NULL_SELECTOR, -1, -1, -1, localCallOffset, s->_executionStack.size() - 1,
 							EXEC_STACK_TYPE_CALL);
 
 			s->_executionStack.push_back(xstack);
diff --git a/engines/sci/engine/vm.h b/engines/sci/engine/vm.h
index 514bf58b64..dc789b6201 100644
--- a/engines/sci/engine/vm.h
+++ b/engines/sci/engine/vm.h
@@ -93,16 +93,19 @@ struct ExecStack {
 
 	SegmentId local_segment; // local variables etc
 
-	Selector debugSelector;   // The selector which was used to call or -1 if not applicable
-	int debugExportId;        // The exportId which was called or -1 if not applicable
-	int debugLocalCallOffset; // Local call offset or -1 if not applicable
-	int debugOrigin;          // The stack frame position the call was made from, or -1 if it was the initial call
+	Selector debugSelector;     // The selector which was used to call or -1 if not applicable
+	int debugExportId;          // The exportId which was called or -1 if not applicable
+	int debugLocalCallOffset;   // Local call offset or -1 if not applicable
+	int debugOrigin;            // The stack frame position the call was made from, or -1 if it was the initial call
+	int debugKernelFunction;    // The kernel function called, or -1 if not applicable
+	int debugKernelSubFunction; // The kernel subfunction called, or -1 if not applicable
 	ExecStackType type;
 
 	reg_t* getVarPointer(SegManager *segMan) const;
 
 	ExecStack(reg_t objp_, reg_t sendp_, StackPtr sp_, int argc_, StackPtr argp_,
 				SegmentId localsSegment_, reg32_t pc_, Selector debugSelector_,
+				int debugKernelFunction_, int debugKernelSubFunction_,
 				int debugExportId_, int debugLocalCallOffset_, int debugOrigin_,
 				ExecStackType type_) {
 		objp = objp_;
@@ -118,6 +121,8 @@ struct ExecStack {
 		else
 			local_segment = pc_.getSegment();
 		debugSelector = debugSelector_;
+		debugKernelFunction = debugKernelFunction_;
+		debugKernelSubFunction = debugKernelSubFunction_;
 		debugExportId = debugExportId_;
 		debugLocalCallOffset = debugLocalCallOffset_;
 		debugOrigin = debugOrigin_;