Subject: [PATCH v2 10/10] mktag doc: update to explain why to use this

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Thu, 26 Nov 2020 23:22:57 +0100

Change the mktag documentation to compare itself to the similar
"hash-object -t tag" command. Before this someone reading the
documentation wouldn't have much of an idea what the difference
was.

Let's make it clear that it's to do with slightly different fsck
validation logic, and cross-link the "mktag" and "hash-object"
documentation to aid discover-ability.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email-masked]>
---
 Documentation/git-hash-object.txt |  4 ++++
 Documentation/git-mktag.txt       | 29 +++++++++++++++++++++++++----
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-hash-object.txt b/Documentation/git-hash-object.txt
index df9e2c58bd..c535661ced 100644
--- a/Documentation/git-hash-object.txt
+++ b/Documentation/git-hash-object.txt
@@ -58,6 +58,10 @@ OPTIONS
 	stress-testing Git itself or reproducing characteristics of corrupt or
 	bogus objects encountered in the wild.
 
+SEE ALSO
+--------
+linkgit:git-mktag[1]
+
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/Documentation/git-mktag.txt b/Documentation/git-mktag.txt
index a158428eb9..3ba15072df 100644
--- a/Documentation/git-mktag.txt
+++ b/Documentation/git-mktag.txt
@@ -3,7 +3,7 @@ git-mktag(1)
 
 NAME
 ----
-git-mktag - Creates a tag object
+git-mktag - Creates a tag object with extra validation

 SYNOPSIS
@@ -13,10 +13,20 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-Reads a tag contents on standard input and creates a tag object
-that can also be used to sign other objects.
 
-The output is the new tag's <object> identifier.
+Reads a tag contents on standard input and creates a tag object. The
+output is the new tag's <object> identifier.
+
+This command accepts a subset of what linkgit:git-hash-object[1] would
+accept with `-t tag --stdin`. I.e. both of these work:
+
+    git mktag <my-tag
+    git hash-object -t tag --stdin <my-tag
+
+The difference between the two is that mktag does the equivalent of a
+linkgit:git-fsck(1) check on its input, and furthermore disallows some
+thing linkgit:git-hash-object[1] would pass, e.g. extra headers in the
+object before the message.
 
 Tag Format
 ----------
@@ -34,6 +44,17 @@ exists, is separated by a blank line from the header.  The
 message part may contain a signature that Git itself doesn't
 care about, but that can be verified with gpg.
 
+HISTORY
+-------
+
+In versions of Git before v2.30.0 the "mktag" command's validation
+logic was subtly different than that of linkgit:git-fsck[1]. It is now
+a strict superset of linkgit:git-fsck[1]'s validation logic.
+
+SEE ALSO
+--------
+linkgit:git-hash-object[1],
+
 GIT
 ---
 Part of the linkgit:git[1] suite
-- 
2.29.2.222.g5d2a92d10f8