tag, branch, for-each-ref: add --ignore-case for sorting and filtering

This options makes sorting ignore case, which is great when you have
branches named bug-12-do-something, Bug-12-do-some-more and
BUG-12-do-what and want to group them together. Sorting externally may
not be an option because we lose coloring and column layout from
git-branch and git-tag.

The same could be said for filtering, but it's probably less important
because you can always go with the ugly pattern [bB][uU][gG]-* if you're
desperate.

You can't have case-sensitive filtering and case-insensitive sorting (or
the other way around) with this though. For branch and tag, that should
be no problem. for-each-ref, as a plumbing, might want finer control.
But we can always add --{filter,sort}-ignore-case when there is a need
for it.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/Documentation/git-tag.txt b/Documentation/git-tag.txt
index 80019c5..76cfe40 100644
--- a/Documentation/git-tag.txt
+++ b/Documentation/git-tag.txt
@@ -108,6 +108,10 @@ OPTIONS
 	variable if it exists, or lexicographic order otherwise. See
 	linkgit:git-config[1].
 
+-i::
+--ignore-case::
+	Sorting and filtering tags are case insensitive.
+
 --column[=<options>]::
 --no-column::
 	Display tag listing in columns. See configuration variable