fast-export: add --signed-tags=warn-strip mode

This issues a warning while stripping signatures from signed tags, which
allows us to use it as default behaviour for remote helpers which cannot
specify how to handle signed tags.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/Documentation/git-fast-export.txt b/Documentation/git-fast-export.txt
index feab7a3..03fc8c3 100644
--- a/Documentation/git-fast-export.txt
+++ b/Documentation/git-fast-export.txt
@@ -27,15 +27,17 @@ OPTIONS
 	Insert 'progress' statements every <n> objects, to be shown by
 	'git fast-import' during import.
 
---signed-tags=(verbatim|warn|strip|abort)::
+--signed-tags=(verbatim|warn|warn-strip|strip|abort)::
 	Specify how to handle signed tags.  Since any transformation
 	after the export can change the tag names (which can also happen
 	when excluding revisions) the signatures will not match.
 +
 When asking to 'abort' (which is the default), this program will die
-when encountering a signed tag.  With 'strip', the tags will be made
-unsigned, with 'verbatim', they will be silently exported
-and with 'warn', they will be exported, but you will see a warning.
+when encountering a signed tag.  With 'strip', the tags will silently
+be made unsigned, with 'warn-strip' they will be made unsigned but a
+warning will be displayed, with 'verbatim', they will be silently
+exported and with 'warn', they will be exported, but you will see a
+warning.
 
 --tag-of-filtered-object=(abort|drop|rewrite)::
 	Specify how to handle tags whose tagged object is filtered out.