Additional checks for incorrect index data when deleting from mbox

diff --git a/mailboxes/boxes-lib.pl b/mailboxes/boxes-lib.pl
index dcefbd3..981791f 100644 (file)
--- a/mailboxes/boxes-lib.pl
+++ b/mailboxes/boxes-lib.pl
@@ -651,12 +651,20 @@ delete($_[0]->{'body'}) if (!$_[2]);
 # Delete mail messages from a user by copying the file and rebuilding the index
 sub delete_mail
 {
+# Validate messages
 local @m = sort { $a->{'line'} <=> $b->{'line'} } @_[1..@_-1];
+foreach my $m (@m) {
+       defined($m->{'line'}) && defined($m->{'eline'}) &&
+         $m->{'eline'} > $m->{'line'} ||
+           &error("Message to delete is invalid, perhaps to due to ".
+                  "out-of-date index");
+       }
+
 local $i = 0;
 local $f = &user_mail_file($_[0]);
 local $ifile = &user_index_file($_[0]);
 local $lnum = 0;
-local %dline;
+local (%dline, @fline);
 local ($dpos = 0, $dlnum = 0);
 local (@index, %index);
 &build_dbm_index($_[0], \%index);
@@ -669,6 +677,7 @@ open(SOURCE, $f) || &error("Read failed : $!");
 open(DEST, ">$tmpf") || &error("Open of $tmpf failed : $!");
 while(<SOURCE>) {
        if ($i >= @m || $lnum < $m[$i]->{'line'}) {
+               # Within a range that we want to preserve
                $dpos += length($_);
                $dlnum++;
                local $w = (print DEST $_);
@@ -680,7 +689,19 @@ while(<SOURCE>) {
                        &error("Write to $tmpf failed : $e");
                        }
                }
+       elsif (!$fline[$i]) {
+               # Start line of a message to delete
+               if (!/^From\s/) {
+                       # Not actually a message! Fail now
+                       close(DEST);
+                       close(SOURCE);
+                       unlink($tmpf);
+                       &error("Index on $f is corrupt - did not find expected mesage start at line $lnum");
+                       }
+               $fline[$i] = 1;
+               }
        elsif ($lnum == $m[$i]->{'eline'}) {
+               # End line of the current message to delete
                $dline{$m[$i]->{'line'}}++;
                $i++;
                }