Improve regex and fix pcall not returning (#2186)

* Improve regex and fix pcall not returning

* Don't use %b

Author: thegrb93

lua/entities/gmod_wire_expression2/core/string.lua

@@ -338,12 +338,18 @@ end)
 /******************************************************************************/
 
 local function checkregex(data, pattern)
-	local limits = {15000, 500, 150, 70, 40} -- Worst case is about 200ms
-	local n = 0 for i in string.gmatch(string.gsub(pattern, "%%.", ""), "[%+%-%*]") do n = n + 1 end
+	local limits = {[0] = 50000000, 15000, 500, 150, 70, 40} -- Worst case is about 200ms
+	-- strip escaped things
+	local stripped, nrepl = string.gsub(pattern, "%%.", "")
+	-- strip bracketed things
+	stripped, nrepl2 = string.gsub(stripped, "%[.-%]", "")
+	-- strip captures
+	stripped = string.gsub(stripped, "[()]", "")
+	-- Find extenders
+	local n = 0 for i in string.gmatch(stripped, "[%+%-%*]") do n = n + 1 end
 	local msg
-	if n==0 then return
-	elseif n<=#limits then
-		if #data>limits[n] then msg = n.." ext search length too long ("..limits[n].." max)" else return end
+	if n<=#limits then
+		if #data*(#stripped + nrepl - n + nrepl2)>limits[n] then msg = n.." ext search length too long ("..limits[n].." max)" else return end
 	else
 		msg = "too many extenders"
 	end
@@ -356,7 +362,7 @@ local find = string.find
 
 --- Returns the 1st occurrence of the string <pattern>, returns 0 if not found. Prints malformed string errors to the chat area.
 e2function number string:findRE(string pattern)
-	local OK, Ret = pcall(function() checkregex(this, pattern) string.find(this, pattern) end)
+	local OK, Ret = pcall(function() checkregex(this, pattern) return string.find(this, pattern) end)
 	if not OK then
 		self.player:ChatPrint(Ret)
 		return 0
@@ -367,7 +373,7 @@ end
 
 ---  Returns the 1st occurrence of the string <pattern> starting at <start> and going to the end of the string, returns 0 if not found. Prints malformed string errors to the chat area.
 e2function number string:findRE(string pattern, start)
-	local OK, Ret = pcall(function() checkregex(this, pattern) find(this, pattern, start) end)
+	local OK, Ret = pcall(function() checkregex(this, pattern) return find(this, pattern, start) end)
 	if not OK then
 		self.player:ChatPrint(Ret)
 		return 0
@@ -394,7 +400,7 @@ end
 
 ---  Finds and replaces every occurrence of <pattern> with <new> using regular expressions. Prints malformed string errors to the chat area.
 e2function string string:replaceRE(string pattern, string new)
-	local OK, Ret = pcall(function() checkregex(this, pattern) gsub(this, pattern, new) end)
+	local OK, Ret = pcall(function() checkregex(this, pattern) return gsub(this, pattern, new) end)
 	if not OK then
 		self.player:ChatPrint(Ret)
 		return ""
@@ -414,7 +420,7 @@ e2function array string:explode(string delim)
 end
 
 e2function array string:explodeRE( string delim )
-	local ok, ret = pcall(function() checkregex(this, pattern) string_Explode( delim, this, true ) end)
+	local ok, ret = pcall(function() checkregex(this, pattern) return string_Explode( delim, this, true ) end)
 	if not ok then
 		self.player:ChatPrint(ret)
 		ret = {}
@@ -453,7 +459,7 @@ local table_remove = table.remove
 
 --- runs [[string.match]](<this>, <pattern>) and returns the sub-captures as an array. Prints malformed pattern errors to the chat area.
 e2function array string:match(string pattern)
-	local args = {pcall(function() checkregex(this, pattern) string_match(this, pattern) end)}
+	local args = {pcall(function() checkregex(this, pattern) return string_match(this, pattern) end)}
 	if not args[1] then
 		self.player:ChatPrint(args[2] or "Unknown error in str:match")
 		return {}
@@ -465,7 +471,7 @@ end
 
 --- runs [[string.match]](<this>, <pattern>, <position>) and returns the sub-captures as an array. Prints malformed pattern errors to the chat area.
 e2function array string:match(string pattern, position)
-	local args = {pcall(function() checkregex(this, pattern) string_match(this, pattern, position) end)}
+	local args = {pcall(function() checkregex(this, pattern) return string_match(this, pattern, position) end)}
 	if not args[1] then
 		self.player:ChatPrint(args[2] or "Unknown error in str:match")
 		return {}
@@ -501,7 +507,7 @@ end
 --- runs [[string.gmatch]](<this>, <pattern>) and returns the captures in an array in a table. Prints malformed pattern errors to the chat area.
 -- (By Divran)
 e2function table string:gmatch(string pattern)
-	local OK, ret = pcall(function() checkregex(this, pattern) gmatch(self, this, pattern) end)
+	local OK, ret = pcall(function() checkregex(this, pattern) return gmatch(self, this, pattern) end)
 	if (!OK) then
 		self.player:ChatPrint( ret or "Unknown error in str:gmatch" )
 		return newE2Table()
@@ -514,7 +520,7 @@ end
 -- (By Divran)
 e2function table string:gmatch(string pattern, position)
 	this = this:Right( -position-1 )
-	local OK, ret = pcall(function() checkregex(this, pattern) gmatch(self, this, pattern) end)
+	local OK, ret = pcall(function() checkregex(this, pattern) return gmatch(self, this, pattern) end)
 	if (!OK) then
 		self.player:ChatPrint( ret or "Unknown error in str:gmatch" )
 		return newE2Table()
@@ -525,7 +531,7 @@ end
 
 --- runs [[string.match]](<this>, <pattern>) and returns the first match or an empty string if the match failed. Prints malformed pattern errors to the chat area.
 e2function string string:matchFirst(string pattern)
-	local OK, Ret = pcall(function() checkregex(this, pattern) string_match(this, pattern) end)
+	local OK, Ret = pcall(function() checkregex(this, pattern) return string_match(this, pattern) end)
 	if not OK then
 		self.player:ChatPrint(Ret)
 		return ""
@@ -536,7 +542,7 @@ end
 
 --- runs [[string.match]](<this>, <pattern>, <position>) and returns the first match or an empty string if the match failed. Prints malformed pattern errors to the chat area.
 e2function string string:matchFirst(string pattern, position)
-	local OK, Ret = pcall(function() checkregex(this, pattern) string_match(this, pattern, position) end)
+	local OK, Ret = pcall(function() checkregex(this, pattern) return string_match(this, pattern, position) end)
 	if not OK then
 		self.player:ChatPrint(Ret)
 		return ""