services: configuration: Step back from *unspecified*.

Fixes <https://issues.guix.gnu.org/56799>.

This partially reverts 8cb1a49a3998c39f315a4199b7d4a121a6d66449.

Rationale: *unspecified* cannot be serialized thus used as a G-Expression
input, which is problematic/inconvenient when using deeply nested records.  As
an example, jami-service-type was broken when using partially defined
<jami-account> records.

* gnu/services/configuration.scm (define-maybe-helper): Check against the
'unset symbol.
(normalize-field-type+def): Adjust value to 'unset.
(define-configuration-helper): Use 'unset as the default value thunk.
* gnu/services/file-sharing.scm (serialize-maybe-string): Check against the
'unset symbol.
(serialize-maybe-file-object): Likewise.
* gnu/services/messaging.scm (define-all-configurations): Use 'unset as
value.
(raw-content?): Check against 'unset symbol.
(prosody-configuration)[http-max-content-size]: Default to 'unset.
[http-external-url]: Likewise.
[mod-muc]: Likewise.
[raw-content]: Likewise.
* gnu/services/networking.scm (opendht-configuration): Adjust documentation.
* gnu/services/telephony.scm (jami-shepherd-services): Replace *undefined*
with the 'unset symbol.
* tests/services/configuration.scm ("maybe type, no default"): Check against
the 'unset symbol.
* doc/guix.texi: Regenerate the opendht-configuration,
openvpn-client-configuration and openvpn-server-configuration documentation.

1 files changed, 6 insertions, 6 deletions

diff --git a/gnu/services/messaging.scm b/gnu/services/messaging.scm
index 651f90adb2..00a1c80a14 100644
--- a/gnu/services/messaging.scm
+++ b/gnu/services/messaging.scm
@@ -90,7 +90,7 @@
                      ((new-def ...)
                       (map (lambda (def target)
                              (if (eq? 'common (syntax->datum target))
-                                 #'*unspecified* def))
+                                 #''unset def))
                            #'(def ...) #'(target ...)))
                      ((new-doc ...)
                       (map (lambda (doc target)
@@ -200,7 +200,7 @@
 (define-maybe file-object-list)
 
 (define (raw-content? val)
-  (not (unspecified? val)))
+  (not (eq? val 'unset)))
 (define (serialize-raw-content field-name val)
   val)
 (define-maybe raw-content)
@@ -474,12 +474,12 @@ by the Prosody service.  See @url{https://prosody.im/doc/logging}."
      global)
 
     (http-max-content-size
-     (maybe-non-negative-integer *unspecified*)
+     (maybe-non-negative-integer 'unset)
      "Maximum allowed size of the HTTP body (in bytes)."
      common)
 
     (http-external-url
-     (maybe-string *unspecified*)
+     (maybe-string 'unset)
      "Some modules expose their own URL in various ways.  This URL is built
 from the protocol, host and port used.  If Prosody sits behind a proxy, the
 public URL will be @code{http-external-url} instead.  See
@@ -556,7 +556,7 @@ support.  To add an external component, you simply fill the hostname field.  See
      int-component)
 
     (mod-muc
-     (maybe-mod-muc-configuration *unspecified*)
+     (maybe-mod-muc-configuration 'unset)
      "Multi-user chat (MUC) is Prosody's module for allowing you to create
 hosted chatrooms/conferences for XMPP users.
 
@@ -573,7 +573,7 @@ See also @url{https://prosody.im/doc/modules/mod_muc}."
      ext-component)
 
     (raw-content
-     (maybe-raw-content *unspecified*)
+     (maybe-raw-content 'unset)
      "Raw content that will be added to the configuration file."
      common)))