system: Add 'create-home-directory?' field to <user-account>.

* gnu/system/shadow.scm (<user-account>)[create-home-directory?]: New
field.
(user-account->gexp): Serialize it.
* gnu/build/activation.scm (activate-users+groups)[activate-user]:
Update 'match-lambda' pattern accordingly.  Pass #:create-home? to
'ensure-user'.
(add-user, modify-user, ensure-user): Add #:create-home? parameter and
honor it.
* doc/guix.texi (User Accounts): Document it.

1 files changed, 4 insertions, 0 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 533023854b..e25cf58a31 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -7223,6 +7223,10 @@ A comment about the account, such as the account owner's full name.
 @item @code{home-directory}
 This is the name of the home directory for the account.
 
+@item @code{create-home-directory?} (default: @code{#t})
+Indicates whether the home directory of this account should be created
+if it does not exist yet.
+
 @item @code{shell} (default: Bash)
 This is a G-expression denoting the file name of a program to be used as
 the shell (@pxref{G-Expressions}).