Detect and handle interrupted syncs to avoid message duplicates.

1 files changed, 32 insertions, 40 deletions

diff --git a/lib/Net/IMAP/Sync.pm b/lib/Net/IMAP/Sync.pm
index 5945746..9882d75 100644
--- a/lib/Net/IMAP/Sync.pm
+++ b/lib/Net/IMAP/Sync.pm
@@ -573,8 +573,8 @@ sub list($$@) {
 #   "UIDPLUS" (RFC 4315) in its CAPABILITY list.
 #   Successfully EXPUNGEd UIDs are removed from the pending VANISHED and
 #   MODIFIED lists.
-#   Return the list of UIDs that could not be EXPUNGEd.
-sub remove($@) {
+#   Return the list of UIDs that couldn't be EXPUNGEd.
+sub remove_message($@) {
     my $self = shift;
     my @set = @_;
     $self->fail("Server did not advertize UIDPLUS (RFC 4315) capability.")
@@ -671,7 +671,7 @@ sub append($$@) {
         delete $vanished2{$_} foreach keys %vanished;
         my $VANISHED = scalar(keys %vanished2); # number of messages VANISHED meanwhile
         $cache->{EXISTS} += $#appends+1 if defined $cache->{EXISTS} and $cache->{EXISTS} + $VANISHED == $EXISTS;
-        $cache->{UIDNEXT} = $UIDNEXT    if ($cache->{UIDNEXT} // 0) < $UIDNEXT;
+        $cache->{UIDNEXT} = $UIDNEXT    if ($cache->{UIDNEXT} // 1) < $UIDNEXT;
     }
 
     $self->log("Added ".($#appends+1)." message(s) to $mailbox, got new UID ".compact_set(@uids))
@@ -852,42 +852,36 @@ sub pull_updates($;$) {
     my $mailbox = $self->{_SELECTED} // $self->panic();
     my $pcache = $self->{_PCACHE}->{$mailbox};
 
-    my (@vanished, %modified);
-    unless (defined $pcache->{UIDNEXT} and defined $pcache->{HIGHESTMODSEQ}) {
-            $self->{_MODIFIED} = {};
-            $self->{_VANISHED} = [];
-    }
-    else {
-        $self->_send("UID FETCH 1:".($pcache->{UIDNEXT}-1)." (MODSEQ FLAGS)")
-            if $full and $pcache->{UIDNEXT} > 1;
-
-        my @missing;
-        while (%{$self->{_MODIFIED}}) {
-            while (my ($uid,$v) = each %{$self->{_MODIFIED}}) {
-                # don't filter on the fly (during FETCH responses) because
-                # FLAG updates can arrive while processing pull_new_messages
-                # for instance
-                if (defined $v->[1] and $v->[0] > 0) { # setting the MODSEQ to 0 forces a FETCH
-                    next unless $uid              < $pcache->{UIDNEXT}         # out of bounds
-                            and ($full or $v->[0] > $pcache->{HIGHESTMODSEQ}); # already seen
-                    $modified{$uid} = $full ? $v : $v->[1];
-                } else {
-                    push @missing, $uid;
-                }
+    my %modified;
+    $self->_send("UID FETCH 1:".($pcache->{UIDNEXT}-1)." (MODSEQ FLAGS)")
+        if $full and ($pcache->{UIDNEXT} // 1) > 1;
+
+    my @missing;
+    while (%{$self->{_MODIFIED}}) {
+        while (my ($uid,$v) = each %{$self->{_MODIFIED}}) {
+            # don't filter on the fly (during FETCH responses) because
+            # FLAG updates can arrive while processing pull_new_messages
+            # for instance
+            if (defined $v->[1] and $v->[0] > 0) { # setting the MODSEQ to 0 forces a FETCH
+                next unless $uid              < ($pcache->{UIDNEXT} // 1)         # out of bounds
+                        and ($full or $v->[0] > ($pcache->{HIGHESTMODSEQ} // 0)); # already seen
+                $modified{$uid} = $full ? $v : $v->[1];
+            } else {
+                push @missing, $uid;
             }
-            $self->{_MODIFIED} = {};
-            $self->_send("UID FETCH ".compact_set(@missing)." (MODSEQ FLAGS)") if @missing;
-            @missing = ();
         }
+        $self->{_MODIFIED} = {};
+        $self->_send("UID FETCH ".compact_set(@missing)." (MODSEQ FLAGS)") if @missing;
+        @missing = ();
+    }
 
-        # do that afterwards since the UID FETCH command above can produce VANISHED responses
-        my %vanished = map {$_ => 1} @{$self->{_VANISHED}};
-        @vanished = keys %vanished;
-        $self->{_VANISHED} = [];
+    # do that afterwards since the UID FETCH command above can produce VANISHED responses
+    my %vanished = map {$_ => 1} grep { $_ < ($pcache->{UIDNEXT} // 1) } @{$self->{_VANISHED}};
+    my @vanished = keys %vanished;
+    $self->{_VANISHED} = [];
 
-        # ignore FLAG updates on VANISHED messages
-        delete @modified{@vanished};
-    }
+    # ignore FLAG updates on VANISHED messages
+    delete @modified{@vanished};
 
     # update the persistent cache for HIGHESTMODSEQ (not for UIDNEXT
     # since there might be new messages)
@@ -1219,7 +1213,7 @@ sub _select_or_examine($$$) {
     $command .= " (QRESYNC ($pcache->{UIDVALIDITY} $pcache->{HIGHESTMODSEQ} "
                            ."1:".($pcache->{UIDNEXT}-1)."))"
         if $self->_enabled('QRESYNC') and
-           ($pcache->{HIGHESTMODSEQ} // 0) > 0 and ($pcache->{UIDNEXT} // 0) > 1;
+           ($pcache->{HIGHESTMODSEQ} // 0) > 0 and ($pcache->{UIDNEXT} // 1) > 1;
 
     if ($self->{_STATE} eq 'SELECTED' and ($self->_capable('CONDSTORE') or $self->_capable('QRESYNC'))) {
         # A mailbox is currently selected and the server advertizes
@@ -1513,15 +1507,13 @@ sub _resp($$;$$$) {
                 if (/\A([0-9]+)\z/) {
                     $cache->{EXISTS}-- unless $earlier; # explicit EXISTS responses are optional
                     $cache->{UIDNEXT} = $1+1 if $cache->{UIDNEXT} <= $1; # the actual UIDNEXT is *at least* that
-                    push @{$self->{_VANISHED}}, $1
-                        if defined $pcache->{UIDNEXT} and $1 < $pcache->{UIDNEXT};
+                    push @{$self->{_VANISHED}}, $1;
                 }
                 elsif (/\A([0-9]+):([0-9]+)\z/) {
                     my ($min, $max) = $1 < $2 ? ($1,$2) : ($2,$1);
                     $cache->{EXISTS} -= $max-$min+1 unless $earlier; # explicit EXISTS responses are optional
                     $cache->{UIDNEXT} = $max+1 if $cache->{UIDNEXT} <= $max; # the actual UIDNEXT is *at least* that
-                    push @{$self->{_VANISHED}}, grep {$_ < $pcache->{UIDNEXT}} ($min .. $max)
-                        if defined $pcache->{UIDNEXT};
+                    push @{$self->{_VANISHED}}, ($min .. $max);
                 }
             }
         }