Support "**" wildcard in .gitignore and .gitattributes

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/gitignore.txt

@@ -96,6 +96,25 @@ PATTERN FORMAT
    For example, "/{asterisk}.c" matches "cat-file.c" but not
    "mozilla-sha1/sha1.c".
 
+Two consecutive asterisks ("`**`") in patterns matched against
+full pathname may have special meaning:
+
+ - A leading "`**`" followed by a slash means match in all
+   directories. For example, "`**/foo`" matches file or directory
+   "`foo`" anywhere, the same as pattern "`foo`". "**/foo/bar"
+   matches file or directory "`bar`" anywhere that is directly
+   under directory "`foo`".
+
+ - A trailing "/**" matches everything inside. For example,
+   "abc/**" matches all files inside directory "abc", relative
+   to the location of the `.gitignore` file, with infinite depth.
+
+ - A slash followed by two consecutive asterisks then a slash
+   matches zero or more directories. For example, "`a/**/b`"
+   matches "`a/b`", "`a/x/b`", "`a/x/y/b`" and so on.
+
+ - Other consecutive asterisks are considered invalid.
+
 NOTES
 -----
 

dir.c

@@ -8,6 +8,7 @@
 #include "cache.h"
 #include "dir.h"
 #include "refs.h"
+#include "wildmatch.h"
 
 struct path_simplify {
 	int len;
@@ -593,7 +594,8 @@ int match_pathname(const char *pathname, int pathlen,
 		namelen -= prefix;
 	}
 
-	return fnmatch_icase(pattern, name, FNM_PATHNAME) == 0;
+	return wildmatch(pattern, name,
+			 ignore_case ? FNM_CASEFOLD : 0) == 0;
 }
 
 /* Scan the list and let the last match determine the fate.

t/t0003-attributes.sh

@@ -216,6 +216,43 @@ test_expect_success 'patterns starting with exclamation' '
 	attr_check "!f" foo
 '
 
+test_expect_success '"**" test' '
+	echo "**/f foo=bar" >.gitattributes &&
+	cat <<\EOF >expect &&
+f: foo: bar
+a/f: foo: bar
+a/b/f: foo: bar
+a/b/c/f: foo: bar
+EOF
+	git check-attr foo -- "f" >actual 2>err &&
+	git check-attr foo -- "a/f" >>actual 2>>err &&
+	git check-attr foo -- "a/b/f" >>actual 2>>err &&
+	git check-attr foo -- "a/b/c/f" >>actual 2>>err &&
+	test_cmp expect actual &&
+	test_line_count = 0 err
+'
+
+test_expect_success '"**" with no slashes test' '
+	echo "a**f foo=bar" >.gitattributes &&
+	git check-attr foo -- "f" >actual &&
+	cat <<\EOF >expect &&
+f: foo: unspecified
+af: foo: bar
+axf: foo: bar
+a/f: foo: unspecified
+a/b/f: foo: unspecified
+a/b/c/f: foo: unspecified
+EOF
+	git check-attr foo -- "f" >actual 2>err &&
+	git check-attr foo -- "af" >>actual 2>err &&
+	git check-attr foo -- "axf" >>actual 2>err &&
+	git check-attr foo -- "a/f" >>actual 2>>err &&
+	git check-attr foo -- "a/b/f" >>actual 2>>err &&
+	git check-attr foo -- "a/b/c/f" >>actual 2>>err &&
+	test_cmp expect actual &&
+	test_line_count = 0 err
+'
+
 test_expect_success 'setup bare' '
 	git clone --bare . bare.git &&
 	cd bare.git

t/t3001-ls-files-others-exclude.sh

@@ -220,4 +220,22 @@ test_expect_success 'pattern matches prefix completely' '
 	test_cmp expect actual
 '
 
+test_expect_success 'ls-files with "**" patterns' '
+	cat <<\EOF >expect &&
+a.1
+one/a.1
+one/two/a.1
+three/a.1
+EOF
+	git ls-files -o -i --exclude "**/a.1" >actual
+	test_cmp expect actual
+'
+
+
+test_expect_success 'ls-files with "**" patterns and no slashes' '
+	: >expect &&
+	git ls-files -o -i --exclude "one**a.1" >actual &&
+	test_cmp expect actual
+'
+
 test_done