ENGINES: Copy the data referenced by QualifiedGameDescriptor

The engineId, gameId and description come from static data in the game
engines. When the game engines are compiled as dynamic plugins, the QGD
structure may outlive the engine plugin. Making a copy ensures the data
remains available.

Fixes #11292.

6 files changed, 15 insertions, 21 deletions

diff --git a/base/commandLine.cpp b/base/commandLine.cpp
index c8ceea77af..bb7f93a274 100644
--- a/base/commandLine.cpp
+++ b/base/commandLine.cpp
@@ -804,7 +804,7 @@ static void listTargets() {
 		// If there's no description, fallback on the default description.
 		if (description.empty()) {
 			QualifiedGameDescriptor g = EngineMan.findTarget(name);
-			if (g.description)
+			if (!g.description.empty())
 				description = g.description;
 		}
 		// If there's still no description, we cannot come up with one. Insert some dummy text.
@@ -854,7 +854,7 @@ static Common::Error listSaves(const Common::String &singleTarget) {
 			currentTarget = *i;
 			EngineMan.upgradeTargetIfNecessary(*i);
 			game = EngineMan.findTarget(*i, &plugin);
-		} else if (game = findGameMatchingName(*i), game.gameId) {
+		} else if (game = findGameMatchingName(*i), !game.gameId.empty()) {
 			// The name is a known game id
 			plugin = EngineMan.findPlugin(game.engineId);
 			currentTarget = createTemporaryTarget(game.engineId, game.gameId);
@@ -1278,7 +1278,7 @@ bool processSettings(Common::String &command, Common::StringMap &settings, Commo
 	QualifiedGameDescriptor gameOption;
 	if (settings.contains("game")) {
 		gameOption = findGameMatchingName(settings["game"]);
-		if (!gameOption.gameId) {
+		if (gameOption.gameId.empty()) {
 			usage("Unrecognized game '%s'. Use the --list-games command for a list of accepted values.\n", settings["game"].c_str());
 		}
 	}
@@ -1361,7 +1361,7 @@ bool processSettings(Common::String &command, Common::StringMap &settings, Commo
 		if (ConfMan.hasGameDomain(command)) {
 			// Command is a known target
 			ConfMan.setActiveDomain(command);
-		} else if (gd = findGameMatchingName(command), gd.gameId) {
+		} else if (gd = findGameMatchingName(command), !gd.gameId.empty()) {
 			// Command is a known game ID
 			Common::String domainName = createTemporaryTarget(gd.engineId, gd.gameId);
 			ConfMan.setActiveDomain(domainName);
diff --git a/base/main.cpp b/base/main.cpp
index 8121d77c88..66ff457936 100644
--- a/base/main.cpp
+++ b/base/main.cpp
@@ -216,7 +216,7 @@ static Common::Error runGame(const Plugin *plugin, OSystem &system, const Common
 
 	if (caption.empty()) {
 		QualifiedGameDescriptor game = EngineMan.findTarget(ConfMan.getActiveDomainName());
-		if (game.description) {
+		if (!game.description.empty()) {
 			caption = game.description;
 		}
 	}
diff --git a/engines/game.cpp b/engines/game.cpp
index b706e1d976..b90381d2d3 100644
--- a/engines/game.cpp
+++ b/engines/game.cpp
@@ -49,18 +49,10 @@ PlainGameDescriptor PlainGameDescriptor::of(const char *gameId, const char *desc
 	return pgd;
 }
 
-QualifiedGameDescriptor::QualifiedGameDescriptor() :
-		PlainGameDescriptor() {
-	engineId    = nullptr;
-	gameId      = nullptr;
-	description = nullptr;
-}
-
 QualifiedGameDescriptor::QualifiedGameDescriptor(const char *engine, const PlainGameDescriptor &pgd) :
-		PlainGameDescriptor() {
-	engineId    = engine;
-	gameId      = pgd.gameId;
-	description = pgd.description;
+		engineId(engine),
+		gameId(pgd.gameId),
+		description(pgd.description) {
 }
 
 DetectedGame::DetectedGame() :
diff --git a/engines/game.h b/engines/game.h
index e378976cb1..8316857e24 100644
--- a/engines/game.h
+++ b/engines/game.h
@@ -66,10 +66,12 @@ public:
 /**
  * The description of a game supported by an engine
  */
-struct QualifiedGameDescriptor : public PlainGameDescriptor {
-	const char *engineId;
+struct QualifiedGameDescriptor {
+	Common::String engineId;
+	Common::String gameId;
+	Common::String description;
 
-	QualifiedGameDescriptor();
+	QualifiedGameDescriptor() {}
 	QualifiedGameDescriptor(const char *engine, const PlainGameDescriptor &pgd);
 };
 
diff --git a/gui/editgamedialog.cpp b/gui/editgamedialog.cpp
index c2953dc8e5..6c553f8783 100644
--- a/gui/editgamedialog.cpp
+++ b/gui/editgamedialog.cpp
@@ -121,7 +121,7 @@ EditGameDialog::EditGameDialog(const String &domain)
 
 	// GAME: Determine the description string
 	String description(ConfMan.get("description", domain));
-	if (description.empty() && qgd.description) {
+	if (description.empty() && !qgd.description.empty()) {
 		description = qgd.description;
 	}
 
diff --git a/gui/launcher.cpp b/gui/launcher.cpp
index 94af6472a5..21937494c4 100644
--- a/gui/launcher.cpp
+++ b/gui/launcher.cpp
@@ -284,7 +284,7 @@ void LauncherDialog::updateListing() {
 
 		if (description.empty()) {
 			QualifiedGameDescriptor g = EngineMan.findTarget(iter->_key);
-			if (g.description)
+			if (!g.description.empty())
 				description = g.description;
 		}