- store CVARs non-destructively in savegames.

The old method using a single string with a backslash as separator is unable to handle anything with actual backslashes in the data.
It now uses a JSON object with each CVAR being a separate key.

src/console/c_cvars.cpp

@@ -44,6 +44,7 @@
 #include "d_player.h"
 #include "v_video.h"
 #include "d_netinf.h"
+#include "serializer.h"
 
 #include "menu/menu.h"
 #include "vm.h"
@@ -1261,6 +1262,47 @@ FString C_GetMassCVarString (uint32_t filter, bool compact)
 	return dump;
 }
 
+void C_SerializeCVars(FSerializer &arc, const char *label, uint32_t filter)
+{
+	FBaseCVar* cvar;
+	FString dump;
+
+	if (arc.BeginObject(label))
+	{
+		if (arc.isWriting())
+		{
+			for (cvar = CVars; cvar != NULL; cvar = cvar->m_Next)
+			{
+				if ((cvar->Flags & filter) && !(cvar->Flags & (CVAR_NOSAVE | CVAR_IGNORE | CVAR_NOSAVEGAME)))
+				{
+					UCVarValue val = cvar->GetGenericRep(CVAR_String);
+					char* c = const_cast<char*>(val.String);
+					arc(cvar->GetName(), c);
+				}
+			}
+		}
+		else
+		{
+			for (cvar = CVars; cvar != NULL; cvar = cvar->m_Next)
+			{
+				if ((cvar->Flags & filter) && !(cvar->Flags & (CVAR_NOSAVE | CVAR_IGNORE | CVAR_NOSAVEGAME)))
+				{
+					UCVarValue val;
+					char *c = nullptr;
+					arc(cvar->GetName(), c);
+					if (c != nullptr)
+					{
+						val.String = c;
+						cvar->SetGenericRep(val, CVAR_String);
+						delete[] c;
+					}
+				}
+			}
+		}
+		arc.EndObject();
+	}
+}
+
 void C_ReadCVars (uint8_t **demo_p)
 {
 	char *ptr = *((char **)demo_p);

src/console/c_cvars.h

@@ -37,6 +37,7 @@
 #include "zstring.h"
 #include "tarray.h"
 
+class FSerializer;
 /*
 ==========================================================
 
@@ -168,6 +169,7 @@ class FBaseCVar
 	static bool m_DoNoSet;
 
 	friend FString C_GetMassCVarString (uint32_t filter, bool compact);
+	friend void C_SerializeCVars(FSerializer& arc, const char* label, uint32_t filter);
 	friend void C_ReadCVars (uint8_t **demo_p);
 	friend void C_BackupCVars (void);
 	friend FBaseCVar *FindCVar (const char *var_name, FBaseCVar **prev);
@@ -191,6 +193,8 @@ void C_WriteCVars (uint8_t **demo_p, uint32_t filter, bool compact=false);
 // Read all cvars from *demo_p and set them appropriately.
 void C_ReadCVars (uint8_t **demo_p);
 
+void C_SerializeCVars(FSerializer& arc, const char* label, uint32_t filter);
+
 // Backup demo cvars. Called before a demo starts playing to save all
 // cvars the demo might change.
 void C_BackupCVars (void);

src/g_game.cpp

@@ -1925,6 +1925,10 @@ void G_DoLoadGame ()
 		uint8_t *vars_p = (uint8_t *)cvar.GetChars();
 		C_ReadCVars(&vars_p);
 	}
+	else
+	{
+		C_SerializeCVars(arc, "servercvars", CVAR_SERVERINFO);
+	}
 
 	uint32_t time[2] = { 1,0 };
 
@@ -2286,11 +2290,7 @@ void G_DoSaveGame (bool okForQuicksave, bool forceQuicksave, FString filename, c
 
 	// Intermission stats for hubs
 	G_SerializeHub(savegameglobals);
-
-	{
-		FString vars = C_GetMassCVarString(CVAR_SERVERINFO);
-		savegameglobals.AddString("importantcvars", vars.GetChars());
-	}
+	C_SerializeCVars(savegameglobals, "servercvars", CVAR_SERVERINFO);
 
 	if (level.time != 0 || level.maptime != 0)
 	{

src/version.h

@@ -88,7 +88,7 @@ const char *GetVersionString();
 
 // Use 4500 as the base git save version, since it's higher than the
 // SVN revision ever got.
-#define SAVEVER 4556
+#define SAVEVER 4557
 
 // This is so that derivates can use the same savegame versions without worrying about engine compatibility
 #define GAMESIG "GZDOOM"