1 files changed, 14 insertions, 2 deletions
diff --git a/src/client/content_cao.cpp b/src/client/content_cao.cpp
index b169ba75f..cf22aa0ed 100644
--- a/src/client/content_cao.cpp
+++ b/src/client/content_cao.cpp
@@ -1062,7 +1062,7 @@ void GenericCAO::updateTexturePos()
 	}
 }
 
-void GenericCAO::updateTextures(std::string mod)
+void GenericCAO::updateTextures(const std::string &modref)
 {
 	ITextureSource *tsrc = m_client->tsrc();
 
@@ -1071,9 +1071,21 @@ void GenericCAO::updateTextures(std::string mod)
 	bool use_anisotropic_filter = g_settings->getBool("anisotropic_filter");
 
 	m_previous_texture_modifier = m_current_texture_modifier;
-	m_current_texture_modifier = mod;
+	m_current_texture_modifier = modref;
 	m_glow = m_prop.glow;
 
+	// Create a reference to the copy of "modref" just created. The
+	// following code will then use this reference instead of the
+	// original parameter which was passed by reference. This is
+	// necessary as "modref" can be a class member and there is a swap on
+	// those class members which can get triggered by the rest of the
+	// code of this method. This is faster than passing the "mod" by
+	// value because it reuses the copy made by the assignment to
+	// m_current_texture_modifier for the "mod" instead of having two
+	// copies, one for "mod" and another one (created from "mod") for
+	// the m_current_texture_modifier class member.
+	const std::string &mod = m_current_texture_modifier;
+
 	video::E_MATERIAL_TYPE material_type = (m_prop.use_texture_alpha) ?
 		video::EMT_TRANSPARENT_ALPHA_CHANNEL : video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF;