diff --git a/Bugzilla/Config.pm b/Bugzilla/Config.pm
index 5639d8603a..b88ef1fc8e 100644
--- a/Bugzilla/Config.pm
+++ b/Bugzilla/Config.pm
@@ -109,13 +109,13 @@ sub update {
       {
         if ($old_value ne $new_value) {
           $dbh->do('UPDATE params SET value = ? WHERE name = ?', undef, $new_value, $key);
-          $changes{"$id:$key"} = [$old_value, $new_value];
+          $changes{$key} = [$old_value, $new_value];
         }
       }
       else {
         $dbh->do('INSERT INTO params (name, value) VALUES (?, ?)',
           undef, $key, $new_value);
-        $changes{"$id:$key"} = ['', $new_value];
+        $changes{$key} = ['', $new_value];
       }
     }
 
@@ -132,10 +132,8 @@ sub update {
     # not the case here so we assign the 'id' variable each interation
     # to make audit_log think each is a separate instance of
     # Bugzilla::Config and each change is a separate transaction.
-    foreach my $item (keys %changes) {
-      my ($id, $key) = split /:/, $item;
-      $self->{id} = $id;
-      $self->audit_log({$key => [$changes{$item}->[0], $changes{$item}->[1]]});
+    foreach my $key (keys %changes) {
+      $self->audit_log({$key => [$changes{$key}->[0], $changes{$key}->[1]]});
     }
   }
   catch {
@@ -301,7 +299,7 @@ sub migrate_params {
   }
 
   # Generate unique Duo integration secret key
-  if ($param->{duo_akey} eq '') {
+  if (!exists $param->{duo_akey} || $param->{duo_akey} eq '') {
     require Bugzilla::Util;
     $param->{duo_akey} = Bugzilla::Util::generate_random_password(40);
   }
diff --git a/Bugzilla/DB/Schema/Mysql.pm b/Bugzilla/DB/Schema/Mysql.pm
index 02526887df..28546f5ce7 100644
--- a/Bugzilla/DB/Schema/Mysql.pm
+++ b/Bugzilla/DB/Schema/Mysql.pm
@@ -155,7 +155,7 @@ sub _get_create_index_ddl {
 
   my $sql = "CREATE ";
   $sql .= "$index_type "
-    if ($index_type eq 'UNIQUE' || $index_type eq 'FULLTEXT');
+    if ($index_type && ($index_type eq 'UNIQUE' || $index_type eq 'FULLTEXT'));
   $sql
     .= "INDEX "
     . $dbh->quote_identifier($index_name) . " ON "
diff --git a/extensions/BMO/Extension.pm b/extensions/BMO/Extension.pm
index 0f27499d64..b6bbcf7af5 100755
--- a/extensions/BMO/Extension.pm
+++ b/extensions/BMO/Extension.pm
@@ -410,7 +410,7 @@ sub parse_bounty_attachment_description {
     fixed_date     => $+{fixed_date} // '',
     awarded_date   => $+{awarded_date} // '',
     publish        => $map{$+{publish} // 'false'},
-    credit         => [grep {$_} split(/\s*,\s*/, $+{credits})]
+    credit         => [grep {$_} split(/\s*,\s*/, $+{credits} || '')]
   };
 }
 
diff --git a/t/hash-sig.t b/t/hash-sig.t
index 0c08c18549..27f2259e06 100644
--- a/t/hash-sig.t
+++ b/t/hash-sig.t
@@ -12,7 +12,7 @@ use Bugzilla::Util qw(generate_random_password);
 use Bugzilla::Token qw(issue_hash_sig check_hash_sig);
 use Bugzilla::Localconfig;
 use Test2::V0;
-use Test2::Mock qw(mock);
+use Test2::Tools::Mock qw(mock);
 
 my $site_wide_secret = generate_random_password(256);
 my $Localconfig = mock 'Bugzilla::Localconfig' => (
diff --git a/t/mojo-example.t b/t/mojo-example.t
index 2301ee800f..af6a2ecfb2 100644
--- a/t/mojo-example.t
+++ b/t/mojo-example.t
@@ -43,7 +43,7 @@ my $api_key = issue_api_key('api@mozilla.org')->api_key;
 my $t = Test::Mojo->new('Bugzilla::App');
 
 # we ensure this file exists so the /__lbhearbeat__ test passes.
-$t->app->home->child('__lbheartbeat__')->spurt('httpd OK');
+$t->app->home->child('__lbheartbeat__')->spew('httpd OK');
 
 # Method chaining is used extensively.
 $t->get_ok('/__lbheartbeat__')->status_is(200)->content_is('httpd OK');
diff --git a/template/en/default/bug/process/bugmail.html.tmpl b/template/en/default/bug/process/bugmail.html.tmpl
index f0cabae973..bdd98e9e4e 100644
--- a/template/en/default/bug/process/bugmail.html.tmpl
+++ b/template/en/default/bug/process/bugmail.html.tmpl
@@ -27,6 +27,8 @@
 [% USE Bugzilla %]
 [% PROCESS global/variables.none.tmpl %]
 
+[% recipient_count = 0 IF !recipient_count.defined %]
+
 [% IF recipient_count > 1 %]
   Email sent to [% recipient_count FILTER none %] recipients.
 [% ELSIF recipient_count == 1 %]