7a602d2 · typeable/pandoc

git.iko.soy/typeable/pandoc

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Limit nesting of strong/emph.

7a602d2John MacFarlane15 years ago

src/Text/Pandoc/Parsing.hs+2

compare with master

unifiedsplit

@@ -629,6 +629,7 @@ data ParserState = ParserState

629 { stateParseRaw :: Bool, -- ^ Parse raw HTML and LaTeX?

630 stateParserContext :: ParserContext, -- ^ Inside list?

631 stateQuoteContext :: QuoteContext, -- ^ Inside quoted environment?

632+ stateMaxNestingLevel :: Int, -- ^ Max # of nested Strong/Emph

632 stateLastStrPos :: Maybe SourcePos, -- ^ Position after last str parsed

633 stateLastStrPos :: Maybe SourcePos, -- ^ Position after last str parsed

633 stateKeys :: KeyTable, -- ^ List of reference keys

634 stateKeys :: KeyTable, -- ^ List of reference keys

634 stateCitations :: [String], -- ^ List of available citations

635 stateCitations :: [String], -- ^ List of available citations

@@ -660,6 +661,7 @@ defaultParserState =

660 ParserState { stateParseRaw = False,

661 ParserState { stateParseRaw = False,

661 stateParserContext = NullState,

662 stateParserContext = NullState,

662 stateQuoteContext = NoQuote,

663 stateQuoteContext = NoQuote,

664+ stateMaxNestingLevel = 6,

663 stateLastStrPos = Nothing,

665 stateLastStrPos = Nothing,

664 stateKeys = M.empty,

666 stateKeys = M.empty,

665 stateCitations = [],

667 stateCitations = [],

src/Text/Pandoc/Readers/Markdown.hs+14−2

@@ -1041,8 +1041,20 @@ inlinesBetween start end =

1041 where inner = innerSpace <|> (notFollowedBy' whitespace >> inline)

1042 innerSpace = try $ whitespace >>~ notFollowedBy' end

1043

1044+-- This is used to prevent exponential blowups for things like:

1045+-- a**a*a**a*a**a*a**a*a**a*a**a*a**

1046+nested :: GenParser Char ParserState a

1047+ -> GenParser Char ParserState a

1048+nested p = do

1049+ nestlevel <- stateMaxNestingLevel `fmap` getState

1050+ guard $ nestlevel > 0

1051+ updateState $ \st -> st{ stateMaxNestingLevel = stateMaxNestingLevel st - 1 }

1052+ res <- p

1053+ updateState $ \st -> st{ stateMaxNestingLevel = nestlevel }

1054+ return res

1055+

1044emph :: GenParser Char ParserState Inline

1056emph :: GenParser Char ParserState Inline

1045−emph = Emph `liftM`

1057+emph = Emph `fmap` nested

1046 (inlinesBetween starStart starEnd <|> inlinesBetween ulStart ulEnd)

1058 (inlinesBetween starStart starEnd <|> inlinesBetween ulStart ulEnd)

1047 where starStart = char '*' >> lookAhead nonspaceChar

1059 where starStart = char '*' >> lookAhead nonspaceChar

1048 starEnd = notFollowedBy' strong >> char '*'

1060 starEnd = notFollowedBy' strong >> char '*'

@@ -1050,7 +1062,7 @@ emph = Emph `liftM`

1050 ulEnd = notFollowedBy' strong >> char '_'

1062 ulEnd = notFollowedBy' strong >> char '_'

1051

1063

1052strong :: GenParser Char ParserState Inline

1064strong :: GenParser Char ParserState Inline

1053−strong = Strong `liftM`

1065+strong = Strong `liftM` nested

1054 (inlinesBetween starStart starEnd <|> inlinesBetween ulStart ulEnd)

1066 (inlinesBetween starStart starEnd <|> inlinesBetween ulStart ulEnd)

1055 where starStart = string "**" >> lookAhead nonspaceChar

1067 where starStart = string "**" >> lookAhead nonspaceChar

1056 starEnd = try $ string "**"

1068 starEnd = try $ string "**"