GLK: FROTZ: Fixes for saving and restoring in V6 games

7 files changed, 23 insertions, 13 deletions

diff --git a/engines/glk/frotz/mem.cpp b/engines/glk/frotz/mem.cpp
index ea3ca183c7..32e3ab3159 100644
--- a/engines/glk/frotz/mem.cpp
+++ b/engines/glk/frotz/mem.cpp
@@ -29,7 +29,7 @@ namespace Glk {
 namespace Frotz {
 
 Mem::Mem() : story_fp(nullptr), story_size(0), first_undo(nullptr), last_undo(nullptr),
-		curr_undo(nullptr), undo_mem(nullptr), zmp(nullptr), prev_zmp(nullptr),
+		curr_undo(nullptr), undo_mem(nullptr), zmp(nullptr), pcp(nullptr), prev_zmp(nullptr),
 		undo_diff(nullptr), undo_count(0), reserve_mem(0) {
 }
 
diff --git a/engines/glk/frotz/mem.h b/engines/glk/frotz/mem.h
index c58ef658e4..3a927e25b4 100644
--- a/engines/glk/frotz/mem.h
+++ b/engines/glk/frotz/mem.h
@@ -36,13 +36,15 @@ namespace Frotz {
 #define SET_BYTE(addr,v)   zmp[addr] = v
 #define LOW_BYTE(addr,v)   v = zmp[addr]
 
+typedef uint offset_t;
+
 /**
  * Stores undo information
  */
 struct undo_struct {
 	undo_struct *next;
 	undo_struct *prev;
-	long pc;
+	offset_t pc;
 	long diff_size;
 	zword frame_count;
 	zword stack_size;
@@ -150,6 +152,10 @@ public:
 	 * Constructor
 	 */
 	Mem();
+
+	/**
+	 * Destructor
+	 */
 	virtual ~Mem() {}
 
 	/**
diff --git a/engines/glk/frotz/processor.cpp b/engines/glk/frotz/processor.cpp
index b9631c85e4..eebcc606d2 100644
--- a/engines/glk/frotz/processor.cpp
+++ b/engines/glk/frotz/processor.cpp
@@ -293,7 +293,7 @@ void Processor::interpret() {
 }
 
 void Processor::call(zword routine, int argc, zword *args, int ct) {
-	long pc;
+	uint32 pc;
 	zword value;
 	zbyte count;
 	int i;
@@ -357,7 +357,7 @@ void Processor::call(zword routine, int argc, zword *args, int ct) {
 }
 
 void Processor::ret(zword value) {
-	long pc;
+	offset_t pc;
 	int ct;
 
 	if (_sp > _fp)
@@ -369,7 +369,7 @@ void Processor::ret(zword value) {
 	_frameCount--;
 	_fp = _stack + 1 + *_sp++;
 	pc = *_sp++;
-	pc = ((long)*_sp++ << 9) | pc;
+	pc = ((offset_t)*_sp++ << 9) | pc;
 
 	SET_PC(pc);
 
@@ -385,7 +385,7 @@ void Processor::ret(zword value) {
 }
 
 void Processor::branch(bool flag) {
-	long pc;
+	offset_t pc;
 	zword offset;
 	zbyte specifier;
 	zbyte off1;
@@ -539,12 +539,12 @@ void Processor::z_check_arg_count() {
 }
 
 void Processor::z_jump() {
-	long pc;
+	offset_t pc;
 	GET_PC(pc);
 
 	pc += (short)zargs[0] - 2;
 
-	if ((uint)pc >= story_size)
+	if (pc >= story_size)
 		runtimeError(ERR_ILL_JUMP_ADDR);
 
 	SET_PC(pc);
diff --git a/engines/glk/frotz/processor.h b/engines/glk/frotz/processor.h
index 83d24433cf..e992a78100 100644
--- a/engines/glk/frotz/processor.h
+++ b/engines/glk/frotz/processor.h
@@ -1734,7 +1734,10 @@ public:
 	/**
 	 * Return the current program execution offset
 	 */
-	uint getPC() const { return pcp - zmp; }
+	uint getPC() const {
+		assert(pcp);
+		return pcp - zmp;
+	}
 
 	/**
 	 * Set the program execution offset
diff --git a/engines/glk/frotz/processor_buffer.cpp b/engines/glk/frotz/processor_buffer.cpp
index 65f1fdacb5..9473411b51 100644
--- a/engines/glk/frotz/processor_buffer.cpp
+++ b/engines/glk/frotz/processor_buffer.cpp
@@ -167,7 +167,7 @@ void Processor::runtimeError(ErrorCode errNum) {
 
 	if ((_err_report_mode == ERR_REPORT_ALWAYS)
 		|| (_err_report_mode == ERR_REPORT_ONCE && wasfirst)) {
-		long pc;
+		offset_t pc;
 		GET_PC(pc);
 		print_string("Warning: ");
 		print_string(ERR_MESSAGES[errNum - 1]);
diff --git a/engines/glk/frotz/processor_streams.cpp b/engines/glk/frotz/processor_streams.cpp
index 067708fb23..aedec2f6cf 100644
--- a/engines/glk/frotz/processor_streams.cpp
+++ b/engines/glk/frotz/processor_streams.cpp
@@ -535,9 +535,10 @@ void Processor::z_restart() {
 	_frameCount = 0;
 
 	if (h_version != V6 && h_version != V9) {
-		long pc = (long)h_start_pc;
+		offset_t pc = (offset_t)h_start_pc;
 		SET_PC(pc);
 	} else {
+		SET_PC(0);
 		call(h_start_pc, 0, nullptr, 0);
 	}
 
diff --git a/engines/glk/frotz/quetzal.cpp b/engines/glk/frotz/quetzal.cpp
index 53de2933e5..e025b2bcc7 100644
--- a/engines/glk/frotz/quetzal.cpp
+++ b/engines/glk/frotz/quetzal.cpp
@@ -53,7 +53,7 @@ bool Quetzal::read_long(Common::ReadStream *f, uint *result) {
 bool Quetzal::save(Common::WriteStream *svf, Processor *proc, const Common::String &desc) {
 	Processor &p = *proc;
 	uint ifzslen = 0, cmemlen = 0, stkslen = 0, descLen = 0;
-	uint pc;
+	offset_t pc;
 	zword i, j, n;
 	zword nvars, nargs, nstk;
 	zbyte var;
@@ -214,7 +214,7 @@ bool Quetzal::save(Common::WriteStream *svf, Processor *proc, const Common::Stri
 int Quetzal::restore(Common::SeekableReadStream *svf, Processor *proc) {
 	Processor &p = *proc;
 	uint ifzslen, currlen, tmpl;
-	uint pc;
+	offset_t pc;
 	zword i, tmpw;
 	int fatal = 0;	// Set to -1 when errors must be fatal.
 	zbyte skip, progress = GOT_NONE;