uidlformat config option - allow UIDLs like Dovecot or Courier

imap/pop3d.c

@@ -1242,10 +1242,31 @@ int msg_exists_or_err(uint32_t msgno)
 void uidl_msg(uint32_t msgno)
 {
     if (popd_mailbox->i.options & OPT_POP3_NEW_UIDL) {
-        prot_printf(popd_out, "%u %u.%u\r\n", msgno,
-                    popd_mailbox->i.uidvalidity,
-                    popd_map[msgno-1].uid);
-    } else {
+        switch (config_getenum(IMAPOPT_UIDL_FORMAT)) {
+        case IMAP_ENUM_UIDL_FORMAT_UIDONLY:
+            prot_printf(popd_out, "%u %u\r\n", msgno,
+                        popd_map[msgno-1].uid);
+            break;
+        case IMAP_ENUM_UIDL_FORMAT_CYRUS:
+            prot_printf(popd_out, "%u %u.%u\r\n", msgno,
+                        popd_mailbox->i.uidvalidity,
+                        popd_map[msgno-1].uid);
+            break;
+        case IMAP_ENUM_UIDL_FORMAT_DOVECOT:
+            prot_printf(popd_out, "%u %08x%08x\r\n", msgno,
+                        popd_map[msgno-1].uid,
+                        popd_mailbox->i.uidvalidity);
+            break;
+        case IMAP_ENUM_UIDL_FORMAT_COURIER:
+            prot_printf(popd_out, "%u %u-%u\r\n", msgno,
+                        popd_mailbox->i.uidvalidity,
+                        popd_map[msgno-1].uid);
+            break;
+        default:
+            abort();
+        }
+    }
+    else {
         prot_printf(popd_out, "%u %u\r\n", msgno,
                     popd_map[msgno-1].uid);
     }

lib/imapoptions

@@ -2073,6 +2073,12 @@ product version in the capabilities */
    versions of SSL/TLS will need to be added here to allow them to get
    disabled. */
 
+{ "uidl_format", "cyrus", ENUM("uidonly", "cyrus", "dovecot", "courier") }
+/* Choose the format for UIDLs in pop3.  Possible values are "uidonly",
+   "cyrus", "dovecot" and "courier".  "uidonly" forces the old default
+   of UID, "cyrus" is UIDVALIDITY.UID.  Dovecot is 8 digits of leading
+   hex (lower case) each UID UIDVALIDITY. Courier is UIDVALIDITY-UID. */
+
 { "umask", "077", STRING }
 /* The umask value used by various Cyrus IMAP programs. */