WINTERMUTE: Disambiguate empty and NULL strings when saving

The string stored is now strlen(s)+1, with length 0 indicating NULL.

Increment savegame version for this new format.

Old savegames are fixed by assuming VAL_STRING should never be NULL.

1 files changed, 11 insertions, 0 deletions

diff --git a/engines/wintermute/base/scriptables/script_value.cpp b/engines/wintermute/base/scriptables/script_value.cpp
index 3532e127d0..31ec457df1 100644
--- a/engines/wintermute/base/scriptables/script_value.cpp
+++ b/engines/wintermute/base/scriptables/script_value.cpp
@@ -827,6 +827,17 @@ bool ScValue::persist(BasePersistenceManager *persistMgr) {
 	persistMgr->transferPtr(TMEMBER_PTR(_valRef));
 	persistMgr->transfer(TMEMBER(_valString));
 
+	if (!persistMgr->getIsSaving() && !persistMgr->checkVersion(1,2,2)) {
+		// Savegames prior to 1.2.2 stored empty strings as NULL.
+		// We disambiguate those by turning NULL strings into empty
+		// strings if _type is VAL_STRING instead of VAL_NULL.
+
+		if (_type == VAL_STRING && !_valString) {
+			_valString = new char[1];
+			_valString[0] = '\0';
+		}
+	}
+
 	/* // TODO: Convert to Debug-statements.
 	FILE* f = fopen("c:\\val.log", "a+");
 	switch(_type)