Be lenient with extra slashes for CSM paths

clientmods/preview/example.lua

@@ -1,2 +1,2 @@
 print("Loaded example file!, loading more examples")
-dofile(core.get_modpath(core.get_current_modname()) .. "examples/first.lua")
+dofile(core.get_modpath(core.get_current_modname()) .. "/examples/first.lua")

src/client/client.cpp

@@ -1881,8 +1881,17 @@ scene::IAnimatedMesh* Client::getMesh(const std::string &filename, bool cache)
 	return mesh;
 }
 
-const std::string* Client::getModFile(const std::string &filename)
+const std::string* Client::getModFile(std::string filename)
 {
+	// strip dir delimiter from beginning of path
+	auto pos = filename.find_first_of(':');
+	if (pos == std::string::npos)
+		return nullptr;
+	pos++;
+	auto pos2 = filename.find_first_not_of("/", pos);
+	if (pos2 > pos)
+		filename.erase(pos, pos2 - pos);
+
 	StringMap::const_iterator it = m_mod_vfs.find(filename);
 	if (it == m_mod_vfs.end())
 		return nullptr;

src/client/client.h

@@ -378,7 +378,7 @@ public:
 	bool checkLocalPrivilege(const std::string &priv)
 	{ return checkPrivilege(priv); }
 	virtual scene::IAnimatedMesh* getMesh(const std::string &filename, bool cache = false);
-	const std::string* getModFile(const std::string &filename);
+	const std::string* getModFile(std::string filename);
 
 	std::string getModStoragePath() const override;
 	bool registerModStorage(ModMetadata *meta) override;