Merge pull request #10767 from farie82/virology-hotfix

Fixes the virus referencing bug

code/modules/reagents/chemistry/holder.dm

@@ -722,9 +722,10 @@ var/const/INGEST = 2
 	// that could possibly eat up a lot of memory needlessly
 	// if most data lists are read-only.
 	if(trans_data["viruses"])
-		var/list/v = trans_data["viruses"]
-		trans_data["viruses"] = v.Copy()
-
+		var/list/temp = list()
+		for(var/datum/disease/v in trans_data["viruses"])
+			temp.Add(v.Copy())
+		trans_data["viruses"] = temp
 	return trans_data
 
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