Show warning when attempting to load an old savegame (#1941)

planet/System.ocg/LanguageDE.txt

@@ -693,6 +693,7 @@ IDS_MSG_REPLAYPLRS_DESC=In den Hauptrollen
 IDS_MSG_RESOLUTION_DESC=Bildschirmauflösung im Vollbildmodus.
 IDS_MSG_RESTARTCHANGECFG=Änderungen werden erst übernommen, wenn das Spiel neu gestartet wurde.
 IDS_MSG_RNDTEAM=Zufallsteam
+IDS_MSG_SAVEGAMEVERSIONMISMATCH=Dieser Spielstand stammt aus OpenClonk %d.%d und wird mit hoher Warscheinlichkeit mit dieser OpenClonk-Version nicht funktionieren. Trotzdem starten?
 IDS_MSG_SCENARIODESC=Szenariobeschreibung
 IDS_MSG_SCENARIODESC_LOADING=Lade... (%d%%)
 IDS_MSG_SELECT=%s auswählen

planet/System.ocg/LanguageUS.txt

@@ -693,6 +693,7 @@ IDS_MSG_REPLAYPLRS_DESC=Starring
 IDS_MSG_RESOLUTION_DESC=Select screen resolution in fullscreen mode.
 IDS_MSG_RESTARTCHANGECFG=For changes to take effect the program has to be restarted.
 IDS_MSG_RNDTEAM=Random team
+IDS_MSG_SAVEGAMEVERSIONMISMATCH=This savegame was created in OpenClonk %d.%d. It will likely not work with this version of OpenClonk. Start anyways?
 IDS_MSG_SCENARIODESC=Scenario description
 IDS_MSG_SCENARIODESC_LOADING=Loading... (%d%%)
 IDS_MSG_SELECT=Select %s

src/gui/C4StartupScenSelDlg.cpp

@@ -761,7 +761,7 @@ bool C4ScenarioListLoader::Scenario::Start()
 	return (C4StartupScenSelDlg::pInstance)->StartScenario(this);
 }
 
-bool C4ScenarioListLoader::Scenario::CanOpen(StdStrBuf &sErrOut)
+bool C4ScenarioListLoader::Scenario::CanOpen(StdStrBuf &sErrOut, bool &CanHide)
 {
 	// safety
 	C4StartupScenSelDlg *pDlg = C4StartupScenSelDlg::pInstance;
@@ -793,6 +793,14 @@ bool C4ScenarioListLoader::Scenario::CanOpen(StdStrBuf &sErrOut)
 			// Some scenarios have adjusted MaxPlayerCount to 0 after starting to prevent future joins
 			// make sure it's possible to start the savegame anyway
 			iMaxPlrCount = std::max<int32_t>(iMinPlrCount, iMaxPlrCount);
+
+			// <Sven2> Savegames store a lot of internal stuff. If you updated clonk in the meantime, many things tend to break
+			if (C4S.Head.C4XVer[0] != C4XVER1 || C4S.Head.C4XVer[1] != C4XVER2)
+			{
+				// Only show a warning to let players try it anyways.
+				sErrOut.Format(LoadResStr("IDS_MSG_SAVEGAMEVERSIONMISMATCH"), C4S.Head.C4XVer[0], C4S.Head.C4XVer[1]);
+				CanHide = false;
+			}
 		}
 		// normal scenarios: At least one player except in network mode, where it is possible to wait for the additional players
 		// Melees need at least two
@@ -803,6 +811,7 @@ bool C4ScenarioListLoader::Scenario::CanOpen(StdStrBuf &sErrOut)
 				// network game: Players may yet join in lobby
 				// only issue a warning for too few players (by setting the error but not returning false here)
 				sErrOut.Format(LoadResStr("IDS_MSG_TOOFEWPLAYERSNET"), (int) iMinPlrCount);
+				CanHide = true;
 			}
 			else
 			{
@@ -1298,8 +1307,8 @@ C4StartupScenSelDlg::ScenListItem::ScenListItem(C4GUI::ListBox *pForListBox, C4S
 {
 	assert(pScenListEntry);
 	CStdFont &rUseFont = C4Startup::Get()->Graphics.BookFont;
-	StdStrBuf sIgnore;
-	bool fEnabled = pScenListEntry->CanOpen(sIgnore) && !pScenListEntry->IsGrayed();
+	StdStrBuf sIgnore; bool bIgnore;
+	bool fEnabled = pScenListEntry->CanOpen(sIgnore, bIgnore) && !pScenListEntry->IsGrayed();
 	// calc height
 	int32_t iHeight = rUseFont.GetLineHeight() + 2 * IconLabelSpacing;
 	// create subcomponents
@@ -1779,7 +1788,8 @@ bool C4StartupScenSelDlg::DoOK()
 	if (!pSel) return false;
 	// check if open is possible
 	StdStrBuf sError;
-	if (!pSel->CanOpen(sError))
+	bool CanHide = false;
+	if (!pSel->CanOpen(sError, CanHide))
 	{
 		GetScreen()->ShowMessage(sError.getData(), LoadResStr("IDS_MSG_CANNOTSTARTSCENARIO"), C4GUI::Ico_Error);
 		return false;
@@ -1787,7 +1797,7 @@ bool C4StartupScenSelDlg::DoOK()
 	// if CanOpen returned true but set an error message, that means it's a warning. Display it!
 	if (sError.getLength())
 	{
-		if (!GetScreen()->ShowMessageModal(sError.getData(), LoadResStrNoAmp("IDS_DLG_STARTGAME"), C4GUI::MessageDialog::btnOKAbort, C4GUI::Ico_Notify, &Config.Startup.HideMsgStartDedicated))
+		if (!GetScreen()->ShowMessageModal(sError.getData(), LoadResStrNoAmp("IDS_DLG_STARTGAME"), C4GUI::MessageDialog::btnOKAbort, C4GUI::Ico_Notify, CanHide ? &Config.Startup.HideMsgStartDedicated : nullptr))
 			// user chose to not start it
 			return false;
 	}

src/gui/C4StartupScenSelDlg.h

@@ -88,7 +88,7 @@ public:
 
 		static Entry *CreateEntryForFile(const StdStrBuf &sFilename, C4ScenarioListLoader *pLoader, Folder *pParent); // create correct entry type based on file extension
 
-		virtual bool CanOpen(StdStrBuf &sError) { return true; } // whether item can be started/opened (e.g. mission access, unregistered)
+		virtual bool CanOpen(StdStrBuf &sError, bool &CanHide) { return true; } // whether item can be started/opened (e.g. mission access, unregistered)
 		virtual bool IsGrayed() { return false; } // additional condition for graying out - notice unreg folders are grayed but can still be opened
 		virtual bool IsHidden() { return false; } // condition for hiding element completely
 		virtual bool HasMissionAccess() const { return true; }
@@ -126,7 +126,7 @@ public:
 		bool LoadCustomPre(C4Group &rGrp) override; // load scenario core
 		bool Start() override; // launch scenario!
 
-		bool CanOpen(StdStrBuf &sError) override; // check mission access, player count, etc.
+		bool CanOpen(StdStrBuf &sError, bool &CanHide) override; // check mission access, player count, etc.
 		bool IsGrayed() override { return false; } // additional option for graying out
 		bool IsHidden() override { return C4S.Head.Secret && !HasMissionAccess(); } // condition for hiding element completely
 		bool HasMissionAccess() const override { return !fNoMissionAccess; };         // check mission access only
@@ -176,7 +176,7 @@ public:
 		void Resort() { Sort(); }
 		Entry *FindEntryByName(const char *szFilename) const; // find entry by filename comparison
 
-		bool CanOpen(StdStrBuf &sError) override { return true; } // can always open folders
+		bool CanOpen(StdStrBuf &sError, bool &CanHide) override { return true; } // can always open folders
 		bool IsGrayed() override; // unreg folders can be opened to view stuff but they are still grayed out for clarity
 		StdStrBuf GetOpenText() override; // get open button text
 		StdStrBuf GetOpenTooltip() override;