Added plugin priority so there's just one plugin that provides a module functionality.

svn-id: r32121

2 files changed, 23 insertions, 14 deletions

diff --git a/base/plugins.cpp b/base/plugins.cpp
index 7dae94e006..ac8e498469 100644
--- a/base/plugins.cpp
+++ b/base/plugins.cpp
@@ -317,16 +317,26 @@ bool PluginManager::tryLoadPlugin(Plugin *plugin) {
 	assert(plugin);
 	// Try to load the plugin
 	if (plugin->loadPlugin()) {
-		// If successful, add it to the list of known plugins and return.
-		_plugins[plugin->getType()].push_back(plugin);
-
-		// TODO/FIXME: We should perform some additional checks here:
-		// * Check for some kind of "API version" (possibly derived from the
-		//   SVN tree revision?)
-		// * If two plugins provide the same engine, we should only load one.
-		//   To detect this situation, we could just compare the plugin name.
-		//   To handle it, simply prefer modules loaded earlier to those coming.
-		//   Or vice versa... to be determined... :-)
+		// The plugin is valid, see if it provides the same module as an
+		// already loaded one and should replace it.
+		bool found = false;
+
+		PluginList::iterator pl = _plugins[plugin->getType()].begin();
+		while (!found && pl != _plugins[plugin->getType()].end()) {
+			if (!strcmp(plugin->getName(), (*pl)->getName())) {
+				// Found a duplicated module. Replace the old one.
+				found = true;
+				delete *pl;
+				*pl = plugin;
+				debug(1, "Replaced the duplicated plugin: '%s'", plugin->getName());
+			}
+			pl++;
+		}
+
+		if (!found) {
+			// If it provides a new module, just add it to the list of known plugins.
+			_plugins[plugin->getType()].push_back(plugin);
+		}
 
 		return true;
 	} else {
diff --git a/base/plugins.h b/base/plugins.h
index b64334074c..d03a240922 100644
--- a/base/plugins.h
+++ b/base/plugins.h
@@ -27,9 +27,8 @@
 #define BASE_PLUGINS_H
 
 #include "common/error.h"
-#include "common/list.h"
 #include "common/singleton.h"
-#include "base/game.h"
+#include "common/util.h"
 
 #ifdef DYNAMIC_MODULES
 #include "common/fs.h"
@@ -69,7 +68,7 @@ enum PluginType {
 };
 
 // TODO: Make the engine API version depend on ScummVM's version
-// because of the backlinking
+// because of the backlinking (posibly from the SVN revision)
 #define PLUGIN_TYPE_ENGINE_VERSION 1
 #define PLUGIN_TYPE_MIDI_VERSION 1
 
@@ -274,7 +273,7 @@ protected:
  * managing all Plugin class instances, and unloading them.
  */
 class PluginManager : public Common::Singleton<PluginManager> {
-	typedef Common::List<PluginProvider *> ProviderList;
+	typedef Common::Array<PluginProvider *> ProviderList;
 private:
 	PluginList _plugins[PLUGIN_TYPE_MAX];
 	ProviderList _providers;