[PATCH 6/8] wildmatch: adjust "**" behavior

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Standard wildmatch() sees consecutive asterisks as "*" that can also
match slashes. But that may be hard to explain to users as
"abc/**/def" can match "abcdef", "abcxyzdef", "abc/def", "abc/x/def",
"abc/x/y/def"...

This patch changes wildmatch so that users can do

- "**/def" -> all paths ending with file/directory 'def'
- "abc/**" - equivalent to "/abc/"
- "abc/**/def" -> "abc/x/def", "abc/x/y/def"...
- other "**" cases are downgraded to normal "*"

Basically the magic of "**" only remains if it's wrapped around by
slashes.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 t/t3070-wildmatch.sh | 2 +-
 wildmatch.c          | 8 +++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/t/t3070-wildmatch.sh b/t/t3070-wildmatch.sh
index bb92f8d..d320f84 100755
--- a/t/t3070-wildmatch.sh
+++ b/t/t3070-wildmatch.sh
@@ -51,7 +51,7 @@ match 1 1 ']' ']'
 
 # Extended slash-matching features
 match 0 0 'foo/baz/bar' 'foo*bar'
-match 1 0 'foo/baz/bar' 'foo**bar'
+match 0 0 'foo/baz/bar' 'foo**bar'
 match 0 0 'foo/bar' 'foo?bar'
 match 0 0 'foo/bar' 'foo[/]bar'
 match 0 0 'foo/bar' 'f[^eiu][^eiu][^eiu][^eiu][^eiu]r'
diff --git a/wildmatch.c b/wildmatch.c
index fdb8cb1..1b39346 100644
--- a/wildmatch.c
+++ b/wildmatch.c
@@ -91,8 +91,14 @@ static int dowild(const uchar *p, const uchar *text, int force_lower_case)
 	    continue;
 	  case '*':
 	    if (*++p == '*') {
+		const uchar *prev_p = p - 2;
 		while (*++p == '*') {}
-		special = TRUE;
+		if ((prev_p == text || *prev_p == '/') ||
+		    (*p == '\0' || *p == '/' ||
+		     (p[0] == '\\' && p[1] == '/'))) {
+		    special = TRUE;
+		} else
+		    special = FALSE;
 	    } else
 		special = FALSE;
 	    if (*p == '\0') {
-- 
1.8.0.rc0.29.g1fdd78f