patterns: Allow bare words only in arguments

This changes the syntax from approximately

	expr = unary
	unary = '!'? primary
	primary = pattern | short-pattern | word | quoted-word
	pattern = '?' name [ '(' expr [',' expr]* ')' ]
	short-pattern = ~ name | ~name expr
to:

        primary = pattern | short-pattern
        argument = word | quoted-word | expr
        pattern = '?' name [ '(' argument [',' argument]* ')' ]
        short-pattern = ~ name | ~name argument

1 files changed, 1 insertions, 0 deletions

diff --git a/apt-pkg/cachefilter-patterns.h b/apt-pkg/cachefilter-patterns.h
index 76318eafa..1770c7307 100644
--- a/apt-pkg/cachefilter-patterns.h
+++ b/apt-pkg/cachefilter-patterns.h
@@ -99,6 +99,7 @@ struct PatternTreeParser
    std::unique_ptr<Node> parsePrimary();
    std::unique_ptr<Node> parsePattern();
    std::unique_ptr<Node> parseShortPattern();
+   std::unique_ptr<Node> parseArgument();
    std::unique_ptr<Node> parseWord();
    std::unique_ptr<Node> parseQuotedWord();
 };