1 files changed, 24 insertions, 34 deletions

diff --git a/lib/Net/IMAP/InterIMAP.pm b/lib/Net/IMAP/InterIMAP.pm
index c25df27..a838dd0 100644
--- a/lib/Net/IMAP/InterIMAP.pm
+++ b/lib/Net/IMAP/InterIMAP.pm
@@ -1197,16 +1197,15 @@ sub pull_updates($;$) {
     my $mailbox = $self->{_SELECTED} // $self->panic();
     my $pcache = $self->{_PCACHE}->{$mailbox};
 
-    my %modified;
     $self->_send("UID FETCH 1:".($pcache->{UIDNEXT}-1)." (MODSEQ FLAGS)")
         if $full and ($pcache->{UIDNEXT} // 1) > 1;
 
-    my @missing;
+    my %modified;
     while (%{$self->{_MODIFIED}}) {
+        my @missing;
         while (my ($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
+            # 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
@@ -1216,8 +1215,9 @@ sub pull_updates($;$) {
             }
         }
         $self->{_MODIFIED} = {};
+        # non-empty @missing indicates a discouraged (but allowed) CONDSTORE server behavior,
+        # cf. RFC 7162 sec. 3.1.3 ex. 8 and the comment in push_flag_updates() below
         $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
@@ -1307,22 +1307,18 @@ sub push_flag_updates($$@) {
 
     my $mailbox = $self->{_SELECTED} // $self->panic();
     my $modseq = $self->{_PCACHE}->{$mailbox}->{HIGHESTMODSEQ} // $self->panic();
-    my $command = "UID STORE ".compact_set(@set)." FLAGS.SILENT ($flags) (UNCHANGEDSINCE $modseq)";
-
-    my %listed;
-    $self->_send($command, sub($){ $listed{shift->{UID}}++; });
+    my $command = "UID STORE ".compact_set(@set)." (UNCHANGEDSINCE $modseq) FLAGS.SILENT ($flags)";
 
     my %failed;
+    $self->_send($command);
     if ($IMAP_text =~ /\A\Q$IMAP_cond\E \[MODIFIED ([0-9,:]+)\] $RE_TEXT_CHAR+\z/) {
         foreach (split /,/, $1) {
             if (/\A([0-9]+)\z/) {
                 $failed{$1} = 1;
-            }
-            elsif (/\A([0-9]+):([0-9]+)\z/) {
+            } elsif (/\A([0-9]+):([0-9]+)\z/) {
                 my ($min, $max) = $1 < $2 ? ($1,$2) : ($2,$1);
                 $failed{$_} = 1 foreach ($min .. $max);
-            }
-            else {
+            } else {
                 $self->panic($_);
             }
         }
@@ -1330,34 +1326,28 @@ sub push_flag_updates($$@) {
 
     my @ok;
     foreach my $uid (@set) {
+        my $modified = $self->{_MODIFIED};
         if ($failed{$uid}) {
-            # $uid was listed in the MODIFIED response code
-            $self->{_MODIFIED}->{$uid} //= [ 0, undef ]; # will be downloaded again in pull_updates
-            delete $self->{_MODIFIED}->{$uid} if
-                # got a FLAG update for $uid; ignore it if it's $flags
-                defined $self->{_MODIFIED}->{$uid}->[1] and
-                $self->{_MODIFIED}->{$uid}->[1] eq $flags;
-        }
-        else {
-            # $uid wasn't listed in the MODIFIED response code
-            next unless defined $self->{_MODIFIED}->{$uid}; # already stored
-            $self->panic() unless defined $listed{$uid} and $listed{$uid} > 0; # sanity check
-            if ($listed{$uid} == 1) {
-                # ignore succesful update
-                delete $self->{_MODIFIED}->{$uid};
-            }
-            elsif ($self->{_MODIFIED}->{$uid}->[1] and $self->{_MODIFIED}->{$uid}->[1] eq $flags) {
-                # got multiple FETCH responses for $uid, the last one with $flags
-                delete $self->{_MODIFIED}->{$uid};
+            # $uid was listed in the MODIFIED response code from RFC 7162; will FETCH
+            # again in pull_updates(); per RFC 7162 sec. 3.1.3 $modified->{$uid} might not
+            # be defined ("nice" servers send an untagged FETCH response, cf. example 10,
+            # but they might omit it - allowed but discouraged CONDSTORE server behavior -
+            # cf. example 8)
+            $modified->{$uid} //= [ 0, undef ];
+        } elsif (defined (my $m = $modified->{$uid})) {
+            # received an untagged FETCH response, remove from the list of pending changes
+            # if the flag list was up to date (either implicitely or explicitely)
+            if (!defined $m->[1] or $m->[1] eq $flags) {
+                delete $modified->{$uid};
+                push @ok, $uid;
             }
-            push @ok, $uid;
         }
     }
 
     unless ($self->{quiet}) {
         $self->log("Updated flags ($flags) for UID ".compact_set(@ok)) if @ok;
         $self->log("Couldn't update flags ($flags) for UID ".compact_set(keys %failed).', '.
-                   "trying again later") if %failed;
+                   "will try again later") if %failed;
     }
     return keys %failed;
 }