Improve chat markdown and regex filters

code/modules/chat_filter/_chat_filter.dm

@@ -7,7 +7,7 @@ var/global/list/chat_modifiers_in_use
 	var/list/all_filters = decls_repository.get_decls_of_type(/decl/chat_filter)
 	for(var/filtertype in all_filters)
 		var/decl/chat_filter/chat_filter = all_filters[filtertype]
-		if(!chat_filter.disabled && chat_filter.filter_category != chat_filter.type)
+		if(!chat_filter.disabled)
 			if(chat_filter.can_deny_message)
 				global.chat_blockers_in_use += chat_filter
 			if(chat_filter.can_modify_message)
@@ -31,10 +31,10 @@ var/global/list/chat_modifiers_in_use
 			. = chat_filter.replace(., match)
 
 /decl/chat_filter
+	abstract_type = /decl/chat_filter
 	var/name
 	var/disabled
 	var/summary
-	var/filter_category = /decl/chat_filter
 	var/can_modify_message = FALSE
 	var/can_deny_message = FALSE
 

code/modules/chat_filter/_chat_filter_regex.dm

@@ -1,6 +1,7 @@
 /decl/chat_filter/regexp
-	filter_category = /decl/chat_filter/regexp
+	abstract_type = /decl/chat_filter/regexp
 	var/regex/filter_regex
 
 /decl/chat_filter/regexp/match(var/message)
-	. = filter_regex && findtext(message, filter_regex)
+	filter_regex.index = 0 // we use the global flag, so we need to reset this for every match or else repeat messages will break
+	. = filter_regex && filter_regex.Find(message)

code/modules/chat_filter/filter_markdown.dm

@@ -1,27 +1,27 @@
 /decl/chat_filter/regexp/markdown
-	filter_category = /decl/chat_filter/regexp/markdown
+	abstract_type = /decl/chat_filter/regexp/markdown
 	can_modify_message = TRUE
 	var/format_char
 	var/format_replace_proc
 
 /decl/chat_filter/regexp/markdown/Initialize()
 	. = ..()
-	filter_regex = regex("([format_char])(.+?)([format_char])", "g")
+	filter_regex = regex("([REGEX_QUOTE(format_char)])(.+?)([REGEX_QUOTE(format_char)])", "g")
 
 /decl/chat_filter/regexp/markdown/replace(var/message, var/match)
 	. = filter_regex.Replace(message, format_replace_proc)
 
 /proc/chatFilterRegexBold(full_match, prefix_char, message_body, suffix_char)
-	. = "<b>[message_body]</b>"
+	. = "<b>[trim(message_body)]</b>"
 
 /decl/chat_filter/regexp/markdown/bold
 	name = "Bold"
 	summary = "Applies <b>bold</b> to speech and emote text that is surrounded by *asterisks*."
-	format_char = "\\*"
+	format_char = "*"
 	format_replace_proc = /proc/chatFilterRegexBold
 
 /proc/chatFilterRegexItalic(full_match, prefix_char, message_body, suffix_char)
-	. = "<i>[message_body]</i>"
+	. = "<i>[trim(message_body)]</i>"
 
 /decl/chat_filter/regexp/markdown/italic
 	name = "Italics"