In KMail2 I have several identities, each of which uses a different signature file.  When I start composing a new message from within KMail2 (by using the "New Message", "Reply", or "Forward" commands), then I get a composer window that gets prefilled (possibly among other material) with the signature of the default identity.  If I select a different identity from the "Identity" drop-down box, then the composer  immediately replaces the signature in the message body with that of the newly selected identity.

However, this feature doesn't work when I create a new message from the command line using the "--msg" or "--body" command-line options.  In this case, selecting a new identity does not replace the signature.

I believe this bug is a regression, as I don't recall it happening with KMail1.

Reproducible: Always

Steps to Reproduce:
1. Configure multiple identities, each with their own signature file.
2. From the command line, type "kmail --msg some_file.txt" or "kmail --body 'Some message'"
3. In the composer window, ensure that View->Identity is checked.
4. Select a different identity from the "Identity" drop-down box.

Actual Results:  
5. The signature in the message body does not get replaced with that of the new identity.

Expected Results:  
5. The signature in the message body should get replaced with that of the new identity.