wildmatch: change behavior of "foo**bar" in WM_PATHNAME mode

In WM_PATHNAME mode (or FNM_PATHNAME), '*' does not match '/' and '**'
can but only in three patterns:

- '**/' matches zero or more leading directories
- '/**/' matches zero or more directories in between
- '/**' matches zero or more trailing directories/files

When '**' is present but not in one of these patterns, the current
behavior is consider the pattern invalid and stop matching. In other
words, 'foo**bar' never matches anything, whatever you throw at it.

This behavior is arguably a bit confusing partly because we can't
really tell the user their pattern is invalid so that they can fix
it. So instead, tolerate it and make '**' act like two regular '*'s
(which is essentially the same as a single asterisk). This behavior
seems more predictable.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/Documentation/gitignore.txt b/Documentation/gitignore.txt
index ff5d7f9ed6..32b227942f 100644
--- a/Documentation/gitignore.txt
+++ b/Documentation/gitignore.txt
@@ -129,7 +129,8 @@ full pathname may have special meaning:
    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.
+ - Other consecutive asterisks are considered regular asterisks and
+   will match according to the previous rules.
 
 NOTES
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