[PATCH v3 4/4] doc: interpret-trailers: fix example

[Kristoffer Haugsbakk <code@khaugsbakk.name>]

We need to provide `--trailer sign` since the command won’t output
anything if you don’t give it an input and/or a
`--trailer`. Furthermore, the message which already contains an s-o-b is
wrong:

    $ git interpret-trailers --trailer sign <msg.txt
    Signed-off-by: Alice <alice@example.com>

    Signed-off-by: Alice <alice@example.com>

This can’t be what was originally intended.

So change the messages in this example to use the typical
“subject/message” file.

Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
---
 Documentation/git-interpret-trailers.txt | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-interpret-trailers.txt b/Documentation/git-interpret-trailers.txt
index d2a23e9161..4b97f812be 100644
--- a/Documentation/git-interpret-trailers.txt
+++ b/Documentation/git-interpret-trailers.txt
@@ -322,16 +322,30 @@ $ git interpret-trailers --trailer 'Cc: Alice <alice@example.com>' --trailer 'Re
   'Signed-off-by: ' already, and show how it works:
 +
 ------------
+$ cat msg1.txt
+subject
+
+message
 $ git config trailer.sign.key "Signed-off-by: "
 $ git config trailer.sign.ifmissing add
 $ git config trailer.sign.ifexists doNothing
 $ git config trailer.sign.cmd 'echo "$(git config user.name) <$(git config user.email)>"'
-$ git interpret-trailers <empty-msg.txt
+$ git interpret-trailers --trailer sign <msg1.txt
+subject
+
+message
 
 Signed-off-by: Bob <bob@example.com>
-$ cat msg.txt
+$ cat msg2.txt
+subject
+
+message
+
 Signed-off-by: Alice <alice@example.com>
-$ git interpret-trailers <msg.txt
+$ git interpret-trailers --trailer sign <msg2.txt
+subject
+
+message
 
 Signed-off-by: Alice <alice@example.com>
 ------------
-- 
2.40.0