Merge branch 'nd/attr-match-optim-more'

Start laying the foundation to build the "wildmatch" after we can
agree on its desired semantics.

* nd/attr-match-optim-more:
  attr: more matching optimizations from .gitignore
  gitignore: make pattern parsing code a separate function
  exclude: split pathname matching code into a separate function
  exclude: fix a bug in prefix compare optimization
  exclude: split basename matching code into a separate function
  exclude: stricten a length check in EXC_FLAG_ENDSWITH case

t/t0003-attributes.sh

@@ -196,6 +196,16 @@ test_expect_success 'root subdir attribute test' '
 	attr_check subdir/a/i unspecified
 '
 
+test_expect_success 'negative patterns' '
+	echo "!f test=bar" >.gitattributes &&
+	test_must_fail git check-attr test -- f
+'
+
+test_expect_success 'patterns starting with exclamation' '
+	echo "\!f test=foo" >.gitattributes &&
+	attr_check "!f" foo
+'
+
 test_expect_success 'setup bare' '
 	git clone --bare . bare.git &&
 	cd bare.git