[PATCH] add: do not accept pathspec magic 'attr'

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

Commit b0db704652 (pathspec: allow querying for attributes -
2017-03-13) adds new pathspec magic 'attr' but only with
match_pathspec(). "git add" has some pathspec related code that still
does not know about 'attr' and will bail out:

    $ git add ':(attr:foo)'
    fatal: BUG:dir.c:1584: unsupported magic 40

A better solution would be making this code support 'attr'. But I
don't know how much work is needed (I'm not familiar with this new
magic). For now, let's simply reject this magic with a friendlier
message:

    $ git add ':(attr:foo)'
    fatal: :(attr:foo): pathspec magic not supported by this command: 'attr'

Reported-by: smaudet@sebastianaudet.com
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Since Brandon is currently unreachable, let's do this for now. I
 might eventually find time to go over pathspec code and see if I can
 add 'attr' support to the rest of the commands, but no promise.

 builtin/add.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/builtin/add.c b/builtin/add.c
index 9916498a29..0b64bcdebe 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -454,7 +454,7 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 	 * Check the "pathspec '%s' did not match any files" block
 	 * below before enabling new magic.
 	 */
-	parse_pathspec(&pathspec, 0,
+	parse_pathspec(&pathspec, PATHSPEC_ATTR,
 		       PATHSPEC_PREFER_FULL |
 		       PATHSPEC_SYMLINK_LEADING_PATH,
 		       prefix, argv);
-- 
2.19.0.rc0.337.ge906d732e7