Fix deletes. Add new tests.

* include/mailutils/sys/mboxrb.h (mu_mboxrb_message): New member: mark
* libproto/mboxrb/mboxrb.c (mu_mboxrb_message_ref): New members:
from_length, env_sender_len, env_date_start.
* libproto/mboxrb/message.c (mboxrb_rescan_unlocked): Update dmp->scan.
Fix NULL dereference.
(mboxrb_rescan): Don't update dmp->scan, see above.
(mailbox_append_message): Write out envelope; use FROMRB filter.
(mboxrb_tracker_sync): Rewrite using mark/sweep technique.

* libproto/mboxrb/tests/Makefile.am: Add new tests.
* libproto/mboxrb/tests/testsuite.at: Include new tests.
* libproto/mboxrb/tests/append.at: New test.
* libproto/mboxrb/tests/delete.at: New test.
* libproto/mboxrb/tests/qget.at: New test.
* libproto/mboxrb/tests/uidnext.at: New test.
* libproto/mboxrb/tests/uidvalidity.at: New test.

10 files changed, 623 insertions, 44 deletions

diff --git a/include/mailutils/sys/mboxrb.h b/include/mailutils/sys/mboxrb.h
index 05e7eb0c4..9ed5310ef 100644
--- a/include/mailutils/sys/mboxrb.h
+++ b/include/mailutils/sys/mboxrb.h
@@ -43,6 +43,7 @@ struct mu_mboxrb_message
   unsigned body_from_escaped:1;  /* True if body is from-escaped (valid if
 				    body_lines_scanned is true) */
   unsigned uid_modified:1;/* UID|uidvalidity|uidnext has been modified */
+  unsigned mark:1;
   
   int attr_flags;         /* Packed "Status:" attribute flags */
 
@@ -60,6 +61,9 @@ struct mu_mboxrb_message_ref
 {
   size_t orig_num;        /* Original message index */
   mu_off_t message_start; /* Start of message */
+  size_t from_length;     /* Length of the From_ line */
+  int env_sender_len;
+  int env_date_start;
   mu_off_t body_start;    /* Start of body */
   mu_off_t message_end;   /* End of message */
   int rescan;
diff --git a/libproto/mboxrb/mboxrb.c b/libproto/mboxrb/mboxrb.c
index e9babd517..4ee684a82 100644
--- a/libproto/mboxrb/mboxrb.c
+++ b/libproto/mboxrb/mboxrb.c
@@ -37,6 +37,7 @@
 #include <mailutils/nls.h>
 #include <mailutils/header.h>
 #include <mailutils/attribute.h>
+#include <mailutils/envelope.h>
 #include <mailutils/util.h>
 #include <mailutils/cctype.h>
 #include <mailutils/sys/folder.h>
@@ -448,7 +449,7 @@ mboxrb_rescan_unlocked (mu_mailbox_t mailbox, mu_off_t offset)
     mboxrb_scan_header,
     mboxrb_scan_body
   } state = mboxrb_scan_init;
-  struct mu_mboxrb_message *dmsg;
+  struct mu_mboxrb_message *dmsg = NULL;
   char *zn, *ti;
   int force_init_uids = 0;
   size_t numlines = 0;
@@ -460,6 +461,11 @@ mboxrb_rescan_unlocked (mu_mailbox_t mailbox, mu_off_t offset)
    && b[sizeof (h) - 1] == ':')
   
 
+  rc = mu_stream_size (mailbox->stream, &dmp->size);
+  if (rc)
+    return rc;
+  if (offset == dmp->size)
+    return 0;
   if (!(dmp->stream_flags & MU_STREAM_READ))
     return 0;
 
@@ -642,24 +648,27 @@ mboxrb_rescan_unlocked (mu_mailbox_t mailbox, mu_off_t offset)
 	mboxrb_dispatch (mailbox, MU_EVT_MAILBOX_PROGRESS, NULL);
     }
 
-  /* Finalize the last message */
-  rc = mu_stream_seek (stream, 0, MU_SEEK_CUR, &dmsg->message_end);
-  if (rc)
+  if (dmsg)
     {
-      mu_debug (MU_DEBCAT_MAILBOX, MU_DEBUG_ERROR,
-		("%s:%s (%s): %s",
-		 __func__, "mu_stream_seek", dmp->name,
-		 mu_strerror (rc)));
-      goto err;
+      /* Finalize the last message */
+      rc = mu_stream_seek (stream, 0, MU_SEEK_CUR, &dmsg->message_end);
+      if (rc)
+	{
+	  mu_debug (MU_DEBCAT_MAILBOX, MU_DEBUG_ERROR,
+		    ("%s:%s (%s): %s",
+		     __func__, "mu_stream_seek", dmp->name,
+		     mu_strerror (rc)));
+	  goto err;
+	}
+      dmsg->message_end--;
+      if (dmsg->uid == 0)
+	force_init_uids = 1;
+      if (force_init_uids)
+	mboxrb_message_alloc_uid (dmsg);
+
+      count = dmp->mesg_count;
+      mboxrb_dispatch (mailbox, MU_EVT_MESSAGE_ADD, &count);
     }
-  dmsg->message_end--;
-  if (dmsg->uid == 0)
-    force_init_uids = 1;
-  if (force_init_uids)
-    mboxrb_message_alloc_uid (dmsg);
-
-  count = dmp->mesg_count;
-  mboxrb_dispatch (mailbox, MU_EVT_MESSAGE_ADD, &count);
   
  err:
   if (rc)
@@ -699,13 +708,6 @@ mboxrb_rescan (mu_mailbox_t mailbox, mu_off_t offset)
   pthread_cleanup_push (mboxrb_cleanup, (void *)mailbox);
 #endif
 
-  rc = mu_stream_size (mailbox->stream, &dmp->size);
-  if (rc != 0)
-    {
-      mu_monitor_unlock (mailbox->monitor);
-      return rc;
-    }
-
   if (mailbox->locker && (rc = mu_locker_lock (mailbox->locker)))
     {
       mu_monitor_unlock (mailbox->monitor);
@@ -973,6 +975,48 @@ mailbox_append_message (mu_mailbox_t mailbox, mu_message_t msg)
 
   do
     {
+      mu_envelope_t env;
+      char *date = NULL;
+      char *sender = NULL;
+
+      rc = mu_message_get_envelope (msg, &env);
+      if (rc)
+	break;
+
+      rc = mu_envelope_aget_sender (env, &sender);
+      if (rc == 0)
+	{
+	  rc = mu_envelope_aget_date (env, &date);
+	  if (rc == 0)
+	    {
+	      rc = mu_message_reconstruct_envelope (msg, &env);
+	      if (rc)
+		break;
+
+	      rc = mu_envelope_aget_sender (env, &sender);
+	      if (rc == 0)
+		{
+		  rc = mu_envelope_aget_date (env, &date);
+		  if (rc)
+		    free (sender);
+		}
+
+	      mu_envelope_destroy (&env, msg);
+	      if (rc)
+		break;
+
+	      rc = mu_stream_printf (mailbox->stream, "From %s %s\n",
+				     sender, date);
+	      free (sender);
+	      free (date);
+	    }
+	  else
+	    free (sender);
+	}
+
+      if (rc)
+	break;
+      
       rc = mu_stream_header_copy (mailbox->stream, istr, exclude_headers);
       if (rc)
 	break;
@@ -996,7 +1040,7 @@ mailbox_append_message (mu_mailbox_t mailbox, mu_message_t msg)
       if (rc)
 	break;
 
-      rc = mu_filter_create (&flt, istr, "DOT",
+      rc = mu_filter_create (&flt, istr, "FROMRB",
 			     MU_FILTER_ENCODE, MU_STREAM_READ);
       mu_stream_destroy (&istr);
       rc = mu_stream_copy (mailbox->stream, flt, 0, NULL);
@@ -1155,16 +1199,22 @@ mboxrb_tracker_sync (struct mu_mboxrb_flush_tracker *trk)
     }
   else
     {
+      /* Mark */
+      for (i = 0; i < trk->mesg_count; i++)
+	dmp->mesg[trk->ref[i].orig_num]->mark = 1;
+      /* Sweep */
+      for (i = 0; i < dmp->mesg_count; i++)
+	if (!dmp->mesg[i]->mark)
+	  mu_mboxrb_message_free (dmp->mesg[i]);
+      /* Reorder */
       for (i = 0; i < trk->mesg_count; i++)
 	{
-	  if (trk->ref[i].orig_num != i)
-	    {
-	      size_t j;
-	      for (j = i; j < trk->ref[i].orig_num; j++)
-		mu_mboxrb_message_free (dmp->mesg[j]);
-	      dmp->mesg[i] = dmp->mesg[trk->ref[i].orig_num];
-	    }
+	  dmp->mesg[i] = dmp->mesg[trk->ref[i].orig_num];
+	  dmp->mesg[i]->mark = 0;
 	  dmp->mesg[i]->message_start = trk->ref[i].message_start;
+	  dmp->mesg[i]->from_length = trk->ref[i].from_length;
+	  dmp->mesg[i]->env_sender_len = trk->ref[i].env_sender_len;
+	  dmp->mesg[i]->env_date_start = trk->ref[i].env_date_start;
 	  dmp->mesg[i]->body_start = trk->ref[i].body_start;
 	  dmp->mesg[i]->message_end = trk->ref[i].message_end;
 	  if (trk->ref[i].rescan)
@@ -1201,6 +1251,9 @@ mboxrb_mailbox_copy_unchanged (struct mu_mboxrb_flush_tracker *trk,
 	  struct mu_mboxrb_message *dmsg = trk->dmp->mesg[i];
 	  struct mu_mboxrb_message_ref *ref = tracker_next_ref (trk, i);
 	  ref->message_start = dmsg->message_start + off;
+	  ref->from_length = dmsg->from_length;
+	  ref->env_sender_len = dmsg->env_sender_len;
+	  ref->env_date_start = dmsg->env_date_start;
 	  ref->body_start = dmsg->body_start + off;
 	  ref->message_end = dmsg->message_end + off;
 	  ref->rescan = 0;
diff --git a/libproto/mboxrb/message.c b/libproto/mboxrb/message.c
index 5735cafa4..ab0457b24 100644
--- a/libproto/mboxrb/message.c
+++ b/libproto/mboxrb/message.c
@@ -546,7 +546,8 @@ msg_header_to_stream (mu_stream_t dst, mu_stream_t src,
 }
 
 static int
-env_to_stream (struct mu_mboxrb_message *dmsg,
+env_to_stream (struct mu_mboxrb_message const *dmsg,
+	       struct mu_mboxrb_message_ref *ref,
 	       mu_envelope_t env, mu_stream_t dst)
 {
   char const *sender, *date;
@@ -554,13 +555,13 @@ env_to_stream (struct mu_mboxrb_message *dmsg,
 
   if ((rc = mu_envelope_sget_sender (env, &sender)) == 0 &&
       (rc = mu_envelope_sget_date (env, &date)) == 0)
-    {
+    {//FIXME
       mu_off_t off;
       rc = mu_stream_printf (dst, "From %s %s\n", sender, date);
       mu_stream_seek (dst, 0, MU_SEEK_CUR, &off);
-      dmsg->from_length = off - dmsg->message_start;
-      dmsg->env_sender_len = strlen (sender);
-      dmsg->env_date_start = strlen (sender) + 6;
+      ref->from_length = off - ref->message_start;
+      ref->env_sender_len = strlen (sender);
+      ref->env_date_start = strlen (sender) + 6;
     }
   
   return rc;
@@ -599,7 +600,7 @@ mu_mboxrb_message_reconstruct (mu_stream_t dest,
   rc = mu_message_get_envelope (dmsg->message, &env);
   if (rc)
     return rc;
-  rc = env_to_stream (dmsg, env, dest);
+  rc = env_to_stream (dmsg, ref, env, dest);
   if (rc)
     return rc;
   
diff --git a/libproto/mboxrb/tests/Makefile.am b/libproto/mboxrb/tests/Makefile.am
index 4f8dfdfb0..abb0d1485 100644
--- a/libproto/mboxrb/tests/Makefile.am
+++ b/libproto/mboxrb/tests/Makefile.am
@@ -38,20 +38,20 @@ nodist_mbop_SOURCES = mbop.c
 ## ------------ ##
 
 TESTSUITE_AT += \
+  append.at\
   autodetect.at\
+  delete.at\
   count.at\
   env.at\
   attr.at\
   header.at\
-  body.at
+  body.at\
+  qget.at\
+  uidvalidity.at\
+  uidnext.at
 #  recent.at\
 #  unseen.at\
-#  uidnext.at\
-#  uidvalidity.at\
 #  uid.at\
-#  qget.at\
-#  append.at\
-#  delete.at\
 #  setattr.at\
 #  notify.at
 
diff --git a/libproto/mboxrb/tests/append.at b/libproto/mboxrb/tests/append.at
new file mode 100644
index 000000000..873daed1b
--- /dev/null
+++ b/libproto/mboxrb/tests/append.at
@@ -0,0 +1,111 @@
+# GNU Mailutils -- a suite of utilities for electronic mail -*- autotest -*-
+# Copyright (C) 2020 Free Software Foundation, Inc.
+#
+# This library is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([append])
+AT_DATA([inbox],
+[From hare@wonder.land Mon Jul 29 22:00:08 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3301
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:06 +0100
+Date: Mon, 29 Jul 2002 22:00:01 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3301@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Invitation
+X-IMAPbase:                   10                    9
+X-UID: 1
+
+Have some wine
+
+From alice@wonder.land Mon Jul 29 22:00:09 2002
+Received: (from alice@wonder.land) 
+	by wonder.land id 3302
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:07 +0100
+Date: Mon, 29 Jul 2002 22:00:02 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3302@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+X-UID: 2
+
+I don't see any wine
+
+From hare@wonder.land Mon Jul 29 22:00:10 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3303
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:08 +0100
+Date: Mon, 29 Jul 2002 22:00:03 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3303@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Re: Invitation
+X-UID: 3
+
+There isn't any
+])
+
+AT_DATA([msg],
+[Received: (from alice@wonder.land) 
+	by wonder.land id 3304
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:09 +0100
+Date: Mon, 29 Jul 2002 22:00:04 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3304@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+
+Then it wasn't very civil of you to offer it
+])
+
+
+AT_DATA([commands],
+[append msg
+count
+4
+uid
+env_date
+env_sender
+headers
+body_text
+])
+AT_CHECK([mbop -m inbox < commands],
+[0],
+[append: OK
+count: 4
+4 current message
+4 uid: 9
+4 env_date: Mon Jul 29 21:00:09 2002
+4 env_sender: alice@wonder.land
+4 headers: Received:(from alice@wonder.land) by wonder.land id 3304 for hare@wonder.land; Mon, 29 Jul 2002 22:00:09 +0100
+Date:Mon, 29 Jul 2002 22:00:04 +0100
+From:Alice  <alice@wonder.land>
+Message-Id:<200207292200.3304@wonder.land>
+To:March Hare  <hare@wonder.land>
+Subject:Re: Invitation
+X-UID:9
+
+4 body_text: Then it wasn't very civil of you to offer it
+
+])
+
+AT_CHECK([
+mbop -m inbox uidvalidity
+],
+[0],
+[uidvalidity: 10
+])
+
+AT_CLEANUP
diff --git a/libproto/mboxrb/tests/delete.at b/libproto/mboxrb/tests/delete.at
new file mode 100644
index 000000000..6873bceb9
--- /dev/null
+++ b/libproto/mboxrb/tests/delete.at
@@ -0,0 +1,112 @@
+# GNU Mailutils -- a suite of utilities for electronic mail -*- autotest -*-
+# Copyright (C) 2020 Free Software Foundation, Inc.
+#
+# This library is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([delete])
+AT_DATA([inbox],
+[From hare@wonder.land Mon Jul 29 22:00:08 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3301
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:06 +0100
+Date: Mon, 29 Jul 2002 22:00:01 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3301@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Invitation
+X-IMAPbase:                   10                    9
+X-UID: 1
+
+Have some wine
+
+From alice@wonder.land Mon Jul 29 22:00:09 2002
+Received: (from alice@wonder.land) 
+	by wonder.land id 3302
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:07 +0100
+Date: Mon, 29 Jul 2002 22:00:02 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3302@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+X-UID: 2
+
+I don't see any wine
+
+From hare@wonder.land Mon Jul 29 22:00:10 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3303
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:08 +0100
+Date: Mon, 29 Jul 2002 22:00:03 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3303@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Re: Invitation
+X-UID: 3
+
+There isn't any
+
+From alice@wonder.land Mon Jul 29 22:00:11 2002
+Received: (from alice@wonder.land) 
+	by wonder.land id 3304
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:09 +0100
+Date: Mon, 29 Jul 2002 22:00:04 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3304@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+X-UID: 4
+
+Then it wasn't very civil of you to offer it
+
+From hare@wonder.land Mon Jul 29 22:00:12 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3305
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:10 +0100
+Date: Mon, 29 Jul 2002 22:00:05 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3305@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Re: Invitation
+X-UID: 5
+
+It wasn't very civil of you to sit down without being invited
+])
+
+AT_DATA([commands],
+[3
+set_deleted
+expunge
+# Message 4 becomes 3 after expunge. Re-select it.
+3
+uid
+headers
+])
+
+AT_CHECK([mbop -m inbox < commands],
+[0],
+[3 current message
+3 set_deleted: OK
+expunge: OK
+3 current message
+3 uid: 4
+3 headers: Received:(from alice@wonder.land) by wonder.land id 3304 for hare@wonder.land; Mon, 29 Jul 2002 22:00:09 +0100
+Date:Mon, 29 Jul 2002 22:00:04 +0100
+From:Alice  <alice@wonder.land>
+Message-Id:<200207292200.3304@wonder.land>
+To:March Hare  <hare@wonder.land>
+Subject:Re: Invitation
+X-UID:4
+
+])
+AT_CLEANUP
diff --git a/libproto/mboxrb/tests/qget.at b/libproto/mboxrb/tests/qget.at
new file mode 100644
index 000000000..30baee8e0
--- /dev/null
+++ b/libproto/mboxrb/tests/qget.at
@@ -0,0 +1,37 @@
+# GNU Mailutils -- a suite of utilities for electronic mail -*- autotest -*-
+# Copyright (C) 2020 Free Software Foundation, Inc.
+#
+# This library is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([qget access])
+
+AT_CHECK([cp $spooldir/mbox1 .])
+AT_CHECK([mbop -r -m mbox1 qget 1309],
+[0],
+[qget: Received: (from bar@dontmailme.org)
+	by dontmailme.org id fERKR9N16790
+	for foobar@nonexistent.net; Fri, 28 Dec 2001 22:18:08 +0200
+Date: Fri, 28 Dec 2001 23:28:08 +0200
+From: Bar <bar@dontmailme.org>
+To: Foo Bar <foobar@nonexistent.net>
+Message-Id: <200112232808.fERKR9N16790@dontmailme.org>
+Subject: Re: Jabberwocky
+
+It seems very pretty, but it's *rather* hard to understand!'
+Somehow it seems to fill my head with ideas -- only I don't
+exactly know what they are!  However, SOMEBODY killed SOMETHING:
+that's clear, at any rate...
+
+])
+AT_CLEANUP
\ No newline at end of file
diff --git a/libproto/mboxrb/tests/testsuite.at b/libproto/mboxrb/tests/testsuite.at
index dc232e899..14e15a12e 100644
--- a/libproto/mboxrb/tests/testsuite.at
+++ b/libproto/mboxrb/tests/testsuite.at
@@ -23,4 +23,11 @@ m4_include([env.at])
 m4_include([attr.at])
 m4_include([header.at])
 m4_include([body.at])
+m4_include([qget.at])
+
+m4_include([delete.at])
+m4_include([append.at])
+
+m4_include([uidvalidity.at])
+m4_include([uidnext.at])
 
diff --git a/libproto/mboxrb/tests/uidnext.at b/libproto/mboxrb/tests/uidnext.at
new file mode 100644
index 000000000..97d936ce7
--- /dev/null
+++ b/libproto/mboxrb/tests/uidnext.at
@@ -0,0 +1,145 @@
+# GNU Mailutils -- a suite of utilities for electronic mail -*- autotest -*-
+# Copyright (C) 2020 Free Software Foundation, Inc.
+#
+# This library is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([UID monotonicity])
+AT_DATA([inbox],
+[From hare@wonder.land Mon Jul 29 22:00:08 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3301
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:06 +0100
+Date: Mon, 29 Jul 2002 22:00:01 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3301@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Invitation
+X-IMAPbase:                   10                    9
+X-UID: 1
+
+Have some wine
+
+From alice@wonder.land Mon Jul 29 22:00:09 2002
+Received: (from alice@wonder.land) 
+	by wonder.land id 3302
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:07 +0100
+Date: Mon, 29 Jul 2002 22:00:02 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3302@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+X-UID: 2
+
+I don't see any wine
+
+From hare@wonder.land Mon Jul 29 22:00:10 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3303
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:08 +0100
+Date: Mon, 29 Jul 2002 22:00:03 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3303@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Re: Invitation
+X-UID: 3
+
+There isn't any
+
+From alice@wonder.land Mon Jul 29 22:00:11 2002
+Received: (from alice@wonder.land) 
+	by wonder.land id 3304
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:09 +0100
+Date: Mon, 29 Jul 2002 22:00:04 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3304@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+X-UID: 4
+
+Then it wasn't very civil of you to offer it
+
+From hare@wonder.land Mon Jul 29 22:00:12 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3305
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:10 +0100
+Date: Mon, 29 Jul 2002 22:00:05 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3305@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Re: Invitation
+X-UID: 5
+
+It wasn't very civil of you to sit down without being invited
+])
+
+AT_CHECK([mbop -m inbox uidnext \; uidvalidity],
+[0],
+[uidnext: 9
+uidvalidity: 10
+])
+
+AT_CHECK([mbop -m inbox 5 \; set_deleted \; expunge],
+[0],
+[5 current message
+5 set_deleted: OK
+expunge: OK
+])
+AT_CHECK([mbop -m inbox uidnext \; uidvalidity],
+[0],
+[uidnext: 9
+uidvalidity: 10
+])
+
+AT_CHECK([mbop -m inbox 3 \; set_deleted \; expunge],
+[0],
+[3 current message
+3 set_deleted: OK
+expunge: OK
+])
+AT_CHECK([mbop -m inbox uidnext \; uidvalidity],
+[0],
+[uidnext: 9
+uidvalidity: 10
+])
+
+AT_DATA([msg],
+[From alice@wonder.land Mon Jul 29 22:00:13 2002
+Received: (from alice@wonder.land) 
+	by wonder.land id 3306
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:11 +0100
+Date: Mon, 29 Jul 2002 22:00:06 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3306@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+
+I didn't know it was YOUR table, it's laid for a
+great many more than three.
+])
+
+AT_CHECK([mbop -m inbox append msg \; count \; 4 \; uid \; uidnext],
+[0],
+[append: OK
+count: 4
+4 current message
+4 uid: 9
+uidnext: 10
+])
+AT_CHECK([mbop -m inbox uidnext \; uidvalidity],
+[0],
+[uidnext: 10
+uidvalidity: 10
+])
+
+AT_CLEANUP
diff --git a/libproto/mboxrb/tests/uidvalidity.at b/libproto/mboxrb/tests/uidvalidity.at
new file mode 100644
index 000000000..060540c8c
--- /dev/null
+++ b/libproto/mboxrb/tests/uidvalidity.at
@@ -0,0 +1,109 @@
+# GNU Mailutils -- a suite of utilities for electronic mail -*- autotest -*-
+# Copyright (C) 2020 Free Software Foundation, Inc.
+#
+# This library is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([uidvalidity])
+AT_DATA([inbox],
+[From hare@wonder.land Mon Jul 29 22:00:08 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3301
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:06 +0100
+Date: Mon, 29 Jul 2002 22:00:01 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3301@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Invitation
+X-IMAPbase:                   10                    9
+X-UID: 1
+
+Have some wine
+
+From alice@wonder.land Mon Jul 29 22:00:09 2002
+Received: (from alice@wonder.land) 
+	by wonder.land id 3302
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:07 +0100
+Date: Mon, 29 Jul 2002 22:00:02 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3302@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+X-UID: 2
+
+I don't see any wine
+
+From hare@wonder.land Mon Jul 29 22:00:10 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3303
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:08 +0100
+Date: Mon, 29 Jul 2002 22:00:03 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3303@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Re: Invitation
+X-UID: 3
+
+There isn't any
+
+From alice@wonder.land Mon Jul 29 22:00:11 2002
+Received: (from alice@wonder.land) 
+	by wonder.land id 3304
+	for hare@wonder.land; Mon, 29 Jul 2002 22:00:09 +0100
+Date: Mon, 29 Jul 2002 22:00:04 +0100
+From: Alice  <alice@wonder.land>
+Message-Id: <200207292200.3304@wonder.land>
+To: March Hare  <hare@wonder.land>
+Subject: Re: Invitation
+X-UID: 4
+
+Then it wasn't very civil of you to offer it
+
+From hare@wonder.land Mon Jul 29 22:00:12 2002
+Received: (from hare@wonder.land) 
+	by wonder.land id 3305
+	for alice@wonder.land; Mon, 29 Jul 2002 22:00:10 +0100
+Date: Mon, 29 Jul 2002 22:00:05 +0100
+From: March Hare  <hare@wonder.land>
+Message-Id: <200207292200.3305@wonder.land>
+To: Alice  <alice@wonder.land>
+Subject: Re: Invitation
+X-UID: 5
+
+It wasn't very civil of you to sit down without being invited
+])
+
+AT_CHECK([mbop -m inbox uidvalidity \; uidnext],
+[0],
+[uidvalidity: 10
+uidnext: 9
+])
+
+AT_CHECK([grep ^X- inbox],
+[0],
+[X-IMAPbase:                   10                    9
+X-UID: 1
+X-UID: 2
+X-UID: 3
+X-UID: 4
+X-UID: 5
+])
+
+AT_CHECK([mbop -m inbox uidvalidity \; uidnext],
+[0],
+[uidvalidity: 10
+uidnext: 9
+])
+
+AT_CLEANUP
+