tag: advise on nested tags

Robert Dailey reported confusion on the mailing list about a nested
tag which was most likely created by mistake. Jeff King noted that
this isn't a very common case and creating a tag-to-a-tag can be a
user-error.

Suggest that it may be a mistake with an advice message when
creating such a tag.  Those who do want to create a tag that point
at another tag regularly can turn it off with the usual advice
mechanism.

Reported-by: Robert Dailey <rcdailey.lists@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Denton Liu <liu.denton@gmail.com>
[jc: fixed test style and tweaked the log message]
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/advice.c b/advice.c
index 567209a..ce5f374 100644
--- a/advice.c
+++ b/advice.c
@@ -26,6 +26,7 @@ int advice_ignored_hook = 1;
 int advice_waiting_for_editor = 1;
 int advice_graft_file_deprecated = 1;
 int advice_checkout_ambiguous_remote_branch_name = 1;
+int advice_nested_tag = 1;
 
 static int advice_use_color = -1;
 static char advice_colors[][COLOR_MAXLEN] = {
@@ -81,6 +82,7 @@ static struct {
 	{ "waitingForEditor", &advice_waiting_for_editor },
 	{ "graftFileDeprecated", &advice_graft_file_deprecated },
 	{ "checkoutAmbiguousRemoteBranchName", &advice_checkout_ambiguous_remote_branch_name },
+	{ "nestedTag", &advice_nested_tag },
 
 	/* make this an alias for backward compatibility */
 	{ "pushNonFastForward", &advice_push_update_rejected }