Bug 22353: Automatic duplicate bug detection on enter_bug.cgi

r=glob, a=mkanat

13 files changed, 400 insertions, 79 deletions

diff --git a/.bzrignore b/.bzrignore
index 277148f38..7ab83e7ad 100644
--- a/.bzrignore
+++ b/.bzrignore
@@ -19,6 +19,7 @@
 /skins/contrib/Dusk/dependency-tree.css
 /skins/contrib/Dusk/duplicates.css
 /skins/contrib/Dusk/editusers.css
+/skins/contrib/Dusk/enter_bug.css
 /skins/contrib/Dusk/help.css
 /skins/contrib/Dusk/panel.css
 /skins/contrib/Dusk/page.css
diff --git a/Bugzilla/Bug.pm b/Bugzilla/Bug.pm
index 6df7363d5..80a4b5933 100644
--- a/Bugzilla/Bug.pm
+++ b/Bugzilla/Bug.pm
@@ -49,7 +49,7 @@ use Bugzilla::Group;
 use Bugzilla::Status;
 use Bugzilla::Comment;
 
-use List::MoreUtils qw(firstidx);
+use List::MoreUtils qw(firstidx uniq);
 use List::Util qw(min first);
 use Storable qw(dclone);
 use URI;
@@ -446,6 +446,87 @@ sub match {
     return $class->SUPER::match(@_);
 }
 
+sub possible_duplicates {
+    my ($class, $params) = @_;
+    my $short_desc = $params->{summary};
+    my $products = $params->{products} || [];
+    my $limit = $params->{limit} || MAX_POSSIBLE_DUPLICATES;
+    $limit = MAX_POSSIBLE_DUPLICATES if $limit > MAX_POSSIBLE_DUPLICATES;
+    $products = [$products] if !ref($products) eq 'ARRAY';
+
+    my $orig_limit = $limit;
+    detaint_natural($limit) 
+        || ThrowCodeError('param_must_be_numeric', 
+                          { function => 'possible_duplicates',
+                            param    => $orig_limit });
+
+    my $dbh = Bugzilla->dbh;
+    my $user = Bugzilla->user;
+    my @words = split(/[\b\s]+/, $short_desc || '');
+    # Exclude punctuation from the array.
+    @words = map { /(\w+)/; $1 } @words;
+    # And make sure that each word is longer than 2 characters.
+    @words = grep { defined $_ and length($_) > 2 } @words;
+
+    return [] if !@words;
+
+    my ($where_sql, $relevance_sql);
+    if ($dbh->FULLTEXT_OR) {
+        my $joined_terms = join($dbh->FULLTEXT_OR, @words);
+        ($where_sql, $relevance_sql) = 
+            $dbh->sql_fulltext_search('bugs_fulltext.short_desc', 
+                                      $joined_terms, 1);
+        $relevance_sql ||= $where_sql;
+    }
+    else {
+        my (@where, @relevance);
+        my $count = 0;
+        foreach my $word (@words) {
+            $count++;
+            my ($term, $rel_term) = $dbh->sql_fulltext_search(
+                'bugs_fulltext.short_desc', $word, $count);
+            push(@where, $term);
+            push(@relevance, $rel_term || $term);
+        }
+
+        $where_sql = join(' OR ', @where);
+        $relevance_sql = join(' + ', @relevance);
+    }
+
+    my $product_ids = join(',', map { $_->id } @$products);
+    my $product_sql = $product_ids ? "AND product_id IN ($product_ids)" : "";
+
+    # Because we collapse duplicates, we want to get slightly more bugs
+    # than were actually asked for.
+    my $sql_limit = $limit + 5;
+
+    my $possible_dupes = $dbh->selectall_arrayref(
+        "SELECT bugs.bug_id AS bug_id, bugs.resolution AS resolution,
+                ($relevance_sql) AS relevance
+           FROM bugs
+                INNER JOIN bugs_fulltext ON bugs.bug_id = bugs_fulltext.bug_id
+          WHERE ($where_sql) $product_sql
+       ORDER BY relevance DESC, bug_id DESC
+          LIMIT $sql_limit", {Slice=>{}});
+
+    my @actual_dupe_ids;
+    # Resolve duplicates into their ultimate target duplicates.
+    foreach my $bug (@$possible_dupes) {
+        my $push_id = $bug->{bug_id};
+        if ($bug->{resolution} && $bug->{resolution} eq 'DUPLICATE') {
+            $push_id = _resolve_ultimate_dup_id($bug->{bug_id});
+        }
+        push(@actual_dupe_ids, $push_id);
+    }
+    @actual_dupe_ids = uniq @actual_dupe_ids;
+    if (scalar @actual_dupe_ids > $limit) {
+        @actual_dupe_ids = @actual_dupe_ids[0..($limit-1)];
+    }
+
+    my $visible = $user->visible_bugs(\@actual_dupe_ids);
+    return $class->new_from_list($visible);
+}
+
 # Docs for create() (there's no POD in this file yet, but we very
 # much need this documented right now):
 #
@@ -1426,23 +1507,7 @@ sub _check_dup_id {
 
     # Make sure a loop isn't created when marking this bug
     # as duplicate.
-    my %dupes;
-    my $this_dup = $dupe_of;
-    my $sth = $dbh->prepare('SELECT dupe_of FROM duplicates WHERE dupe = ?');
-
-    while ($this_dup) {
-        if ($this_dup == $self->id) {
-            ThrowUserError('dupe_loop_detected', { bug_id  => $self->id,
-                                                   dupe_of => $dupe_of });
-        }
-        # If $dupes{$this_dup} is already set to 1, then a loop
-        # already exists which does not involve this bug.
-        # As the user is not responsible for this loop, do not
-        # prevent him from marking this bug as a duplicate.
-        last if exists $dupes{$this_dup};
-        $dupes{$this_dup} = 1;
-        $this_dup = $dbh->selectrow_array($sth, undef, $this_dup);
-    }
+   _resolve_ultimate_dup_id($self->id, $dupe_of, 1);
 
     my $cur_dup = $self->dup_id || 0;
     if ($cur_dup != $dupe_of && Bugzilla->params->{'commentonduplicate'}
@@ -2843,6 +2908,38 @@ sub dup_id {
     return $self->{'dup_id'};
 }
 
+sub _resolve_ultimate_dup_id {
+    my ($bug_id, $dupe_of, $loops_are_an_error) = @_;
+    my $dbh = Bugzilla->dbh;
+    my $sth = $dbh->prepare('SELECT dupe_of FROM duplicates WHERE dupe = ?');
+
+    my $this_dup = $dupe_of || $dbh->selectrow_array($sth, undef, $bug_id);
+    my $last_dup = $bug_id;
+
+    my %dupes;
+    while ($this_dup) {
+        if ($this_dup == $bug_id) {
+            if ($loops_are_an_error) {
+                ThrowUserError('dupe_loop_detected', { bug_id  => $bug_id,
+                                                       dupe_of => $dupe_of });
+            }
+            else {
+                return $last_dup;
+            }
+        }
+        # If $dupes{$this_dup} is already set to 1, then a loop
+        # already exists which does not involve this bug.
+        # As the user is not responsible for this loop, do not
+        # prevent him from marking this bug as a duplicate.
+        return $last_dup if exists $dupes{$this_dup};
+        $dupes{$this_dup} = 1;
+        $last_dup = $this_dup;
+        $this_dup = $dbh->selectrow_array($sth, undef, $this_dup);
+    }
+
+    return $last_dup;
+}
+
 sub actual_time {
     my ($self) = @_;
     return $self->{'actual_time'} if exists $self->{'actual_time'};
diff --git a/Bugzilla/Constants.pm b/Bugzilla/Constants.pm
index 55ef4a0e3..9af9e7b72 100644
--- a/Bugzilla/Constants.pm
+++ b/Bugzilla/Constants.pm
@@ -175,6 +175,7 @@ use File::Basename;
     MAX_FIELD_VALUE_SIZE
     MAX_FREETEXT_LENGTH
     MAX_BUG_URL_LENGTH
+    MAX_POSSIBLE_DUPLICATES
 
     PASSWORD_DIGEST_ALGORITHM
     PASSWORD_SALT_LENGTH
@@ -527,6 +528,10 @@ use constant MAX_FREETEXT_LENGTH => 255;
 # The longest a bug URL in a BUG_URLS field can be.
 use constant MAX_BUG_URL_LENGTH => 255;
 
+# The largest number of possible duplicates that Bug::possible_duplicates
+# will return.
+use constant MAX_POSSIBLE_DUPLICATES => 25;
+
 # This is the name of the algorithm used to hash passwords before storing
 # them in the database. This can be any string that is valid to pass to
 # Perl's "Digest" module. Note that if you change this, it won't take
diff --git a/Bugzilla/DB.pm b/Bugzilla/DB.pm
index 8b8d74c90..8c1aba8dd 100644
--- a/Bugzilla/DB.pm
+++ b/Bugzilla/DB.pm
@@ -73,6 +73,11 @@ use constant ENUM_DEFAULTS => {
     resolution   => ["","FIXED","INVALID","WONTFIX", "DUPLICATE","WORKSFORME"],
 };
 
+# The character that means "OR" in a boolean fulltext search. If empty,
+# the database doesn't support OR searches in fulltext searches.
+# Used by Bugzilla::Bug::possible_duplicates.
+use constant FULLTEXT_OR => '';
+
 #####################################################################
 # Connection Methods
 #####################################################################
diff --git a/Bugzilla/DB/Mysql.pm b/Bugzilla/DB/Mysql.pm
index 13069a78a..4b90a2a34 100644
--- a/Bugzilla/DB/Mysql.pm
+++ b/Bugzilla/DB/Mysql.pm
@@ -40,8 +40,8 @@ For interface details see L<Bugzilla::DB> and L<DBI>.
 =cut
 
 package Bugzilla::DB::Mysql;
-
 use strict;
+use base qw(Bugzilla::DB);
 
 use Bugzilla::Constants;
 use Bugzilla::Install::Util qw(install_string);
@@ -57,8 +57,7 @@ use Text::ParseWords;
 # MAX_COMMENT_LENGTH is big.
 use constant MAX_COMMENTS => 50;
 
-# This module extends the DB interface via inheritance
-use base qw(Bugzilla::DB);
+use constant FULLTEXT_OR => '|';
 
 sub new {
     my ($class, $params) = @_;
diff --git a/Bugzilla/DB/Oracle.pm b/Bugzilla/DB/Oracle.pm
index 6fa7a9869..a671a0e68 100644
--- a/Bugzilla/DB/Oracle.pm
+++ b/Bugzilla/DB/Oracle.pm
@@ -35,16 +35,14 @@ For interface details see L<Bugzilla::DB> and L<DBI>.
 =cut
 
 package Bugzilla::DB::Oracle;
-
 use strict;
+use base qw(Bugzilla::DB);
 
 use DBD::Oracle;
 use DBD::Oracle qw(:ora_types);
 use Bugzilla::Constants;
 use Bugzilla::Error;
 use Bugzilla::Util;
-# This module extends the DB interface via inheritance
-use base qw(Bugzilla::DB);
 
 #####################################################################
 # Constants
@@ -52,6 +50,7 @@ use base qw(Bugzilla::DB);
 use constant EMPTY_STRING  => '__BZ_EMPTY_STR__';
 use constant ISOLATION_LEVEL => 'READ COMMITTED';
 use constant BLOB_TYPE => { ora_type => ORA_BLOB };
+use constant FULLTEXT_OR => ' OR ';
 
 sub new {
     my ($class, $params) = @_;
diff --git a/Bugzilla/User.pm b/Bugzilla/User.pm
index aa01d93a5..6c7be2241 100644
--- a/Bugzilla/User.pm
+++ b/Bugzilla/User.pm
@@ -900,7 +900,7 @@ sub can_enter_product {
       $product && grep($_->name eq $product->name,
                        @{ $self->get_enterable_products });
 
-    return 1 if $can_enter;
+    return $product if $can_enter;
 
     return 0 unless $warn == THROW_ERROR;
 
diff --git a/Bugzilla/WebService/Bug.pm b/Bugzilla/WebService/Bug.pm
index ee5591027..d5c1fab74 100644
--- a/Bugzilla/WebService/Bug.pm
+++ b/Bugzilla/WebService/Bug.pm
@@ -36,6 +36,7 @@ use Bugzilla::Util qw(trick_taint trim);
 use Bugzilla::Version;
 use Bugzilla::Milestone;
 use Bugzilla::Status;
+use Bugzilla::Token qw(issue_hash_token);
 
 #############
 # Constants #
@@ -322,7 +323,7 @@ sub get {
         else {
             $bug = Bugzilla::Bug->check($bug_id);
         }
-        push(@bugs, $self->_bug_to_hash($bug));
+        push(@bugs, $self->_bug_to_hash($bug, $params));
     }
 
     return { bugs => \@bugs, faults => \@faults };
@@ -421,7 +422,28 @@ sub search {
     
     my $bugs = Bugzilla::Bug->match($params);
     my $visible = Bugzilla->user->visible_bugs($bugs);
-    my @hashes = map { $self->_bug_to_hash($_) } @$visible;
+    my @hashes = map { $self->_bug_to_hash($_, $params) } @$visible;
+    return { bugs => \@hashes };
+}
+
+sub possible_duplicates {
+    my ($self, $params) = validate(@_, 'product');
+    my $user = Bugzilla->user;
+
+    # Undo the array-ification that validate() does, for "summary".
+    $params->{summary} || ThrowCodeError('param_required',
+        { function => 'Bug.possible_duplicates', param => 'summary' });
+
+    my @products;
+    foreach my $name (@{ $params->{'product'} || [] }) {
+        my $object = $user->can_enter_product($name, THROW_ERROR);
+        push(@products, $object);
+    }
+
+    my $possible_dupes = Bugzilla::Bug->possible_duplicates(
+        { summary => $params->{summary}, products => \@products,
+          limit   => $params->{limit} });
+    my @hashes = map { $self->_bug_to_hash($_, $params) } @$possible_dupes;
     return { bugs => \@hashes };
 }
 
@@ -617,7 +639,7 @@ sub attachments {
 
 # A helper for get() and search().
 sub _bug_to_hash {
-    my ($self, $bug) = @_;
+    my ($self, $bug, $filters) = @_;
 
     # Timetracking fields are deleted if the user doesn't belong to
     # the corresponding group.
@@ -646,6 +668,11 @@ sub _bug_to_hash {
     $item{'component'}        = $self->type('string', $bug->component);
     $item{'dupe_of'}          = $self->type('int', $bug->dup_id);
 
+    if (Bugzilla->user->id) {
+        my $token = issue_hash_token([$bug->id, $bug->delta_ts]);
+        $item{'update_token'} = $self->type('string', $token);
+    }
+
     # if we do not delete this key, additional user info, including their
     # real name, etc, will wind up in the 'internals' hashref
     delete $item{internals}->{assigned_to_obj};
@@ -659,7 +686,7 @@ sub _bug_to_hash {
         $item{'alias'} = undef;
     }
 
-    return \%item;
+    return filter $filters, \%item;
 }
 
 sub _attachment_to_hash {
diff --git a/js/bug.js b/js/bug.js
new file mode 100644
index 000000000..8cee68efc
--- /dev/null
+++ b/js/bug.js
@@ -0,0 +1,117 @@
+/* The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is the Bugzilla Bug Tracking System.
+ *
+ * The Initial Developer of the Original Code is Everything Solved, Inc.
+ * Portions created by Everything Solved are Copyright (C) 2010 Everything
+ * Solved, Inc. All Rights Reserved.
+ *
+ * Contributor(s): Max Kanat-Alexander <mkanat@bugzilla.org>
+ */
+
+/* This library assumes that the needed YUI libraries have been loaded 
+   already. */
+
+YAHOO.bugzilla.dupTable = {
+    counter: 0,
+    dataSource: null,
+    updateTable: function(dataTable, product_name, summary_field) {
+        if (summary_field.value.length < 4) return;
+
+        YAHOO.bugzilla.dupTable.counter = YAHOO.bugzilla.dupTable.counter + 1;
+        YAHOO.util.Connect.setDefaultPostHeader('application/json', true);
+        var json_object = {
+            version : "1.1",
+            method : "Bug.possible_duplicates",
+            id : YAHOO.bugzilla.dupTable.counter,
+            params : {
+                product : product_name,
+                summary : summary_field.value,
+                limit : 7,
+                include_fields : [ "id", "summary", "status", "resolution",
+                                   "update_token" ]
+            }
+        };
+        var post_data = YAHOO.lang.JSON.stringify(json_object);
+
+        var callback = {
+            success: dataTable.onDataReturnInitializeTable,
+            failure: dataTable.onDataReturnInitializeTable,
+            scope:   dataTable,
+            argument: dataTable.getState() 
+        };
+        dataTable.showTableMessage(dataTable.get("MSG_LOADING"),
+                                   YAHOO.widget.DataTable.CLASS_LOADING);
+        YAHOO.util.Dom.removeClass('possible_duplicates_container',
+                                   'bz_default_hidden');
+        dataTable.getDataSource().sendRequest(post_data, callback);
+    },
+    formatBugLink: function(el, oRecord, oColumn, oData) {
+        el.innerHTML = '<a href="show_bug.cgi?id=' + oData + '">' 
+                       + oData + '</a>';
+    },
+    formatStatus: function(el, oRecord, oColumn, oData) {
+        var resolution = oRecord.getData('resolution');
+        if (resolution) {
+            el.innerHTML = oData + ' ' + resolution;
+        }
+        else {
+            el.innerHTML = oData;
+        }
+    },
+    formatCcButton: function(el, oRecord, oColumn, oData) {
+        var url = 'process_bug.cgi?id=' + oRecord.getData('id') 
+                  + '&addselfcc=1&token=' + escape(oData);
+        var button = document.createElement('button');
+        button.setAttribute('type', 'button');
+        button.innerHTML = YAHOO.bugzilla.dupTable.addCcMessage;
+        button.onclick = function() { window.location = url; return false; };
+        el.appendChild(button);
+    },
+    init_ds: function() {
+        var new_ds = new YAHOO.util.XHRDataSource("jsonrpc.cgi");
+        new_ds.connTimeout = 30000;
+        new_ds.connMethodPost = true;
+        new_ds.connXhrMode = "cancelStaleRequests";
+        new_ds.maxCacheEntries = 3;
+        new_ds.responseSchema = {
+            resultsList : "result.bugs",
+            metaFields : { error: "error", jsonRpcId: "id" },
+        };
+        // DataSource can't understand a JSON-RPC error response, so
+        // we have to modify the result data if we get one.
+        new_ds.doBeforeParseData = 
+            function(oRequest, oFullResponse, oCallback) {
+                if (oFullResponse.error) {
+                    oFullResponse.result = {};
+                    oFullResponse.result.bugs = [];
+                    if (console) {
+                        console.log("JSON-RPC error:", oFullResponse.error);
+                    }
+                }
+                return oFullResponse;
+        }
+
+        this.dataSource = new_ds;
+    },
+    init: function(data) {
+        if (this.dataSource == null) this.init_ds();
+        data.options.initialLoad = false;
+        var dt = new YAHOO.widget.DataTable(data.container, data.columns, 
+            this.dataSource, data.options); 
+        YAHOO.util.Event.on(data.summary_field, 'blur',
+            function(e) {
+                YAHOO.bugzilla.dupTable.updateTable(dt, data.product_name, 
+                    YAHOO.util.Event.getTarget(e))
+            }
+        );
+    },
+};
diff --git a/skins/standard/enter_bug.css b/skins/standard/enter_bug.css
new file mode 100644
index 000000000..2fd79baa4
--- /dev/null
+++ b/skins/standard/enter_bug.css
@@ -0,0 +1,65 @@
+/* The contents of this file are subject to the Mozilla Public
+  * License Version 1.1 (the "License"); you may not use this file
+  * except in compliance with the License. You may obtain a copy of
+  * the License at http://www.mozilla.org/MPL/
+  *
+  * Software distributed under the License is distributed on an "AS
+  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+  * implied. See the License for the specific language governing
+  * rights and limitations under the License.
+  *
+  * The Original Code is the Bugzilla Bug Tracking System.
+  *
+  * The Initial Developer of the Original Code is Netscape Communications
+  * Corporation. Portions created by Netscape are Copyright (C) 1998
+  * Netscape Communications Corporation. All Rights Reserved.
+  *
+  * Contributor(s): Byron Jones <bugzilla@glob.com.au>
+  *                 Christian Reis <kiko@async.com.br>
+  *                 Vitaly Harisov <vitaly@rathedg.com>
+  *                 Svetlana Harisova <light@rathedg.com>
+  *                 Marc Schumann <wurblzap@gmail.com>
+  *                 Pascal Held <paheld@gmail.com>
+  *                 Max Kanat-Alexander <mkanat@bugzilla.org>
+  */
+
+/* These are specified using the class instead of the id so that they
+   don't override the YUI CSS. */
+.enter_bug_form table {
+    border-spacing: 0;
+    border-width: 0;
+}
+.enter_bug_form td, .enter_bug_form th { padding: .25em; }
+.enter_bug_form th { text-align: right; }
+
+/* This makes the "component" column as small as possible (since it
+ * contains only fixed-width content) and the Reporter column
+ * as large as possible, which makes the form not jump around
+ * when the Component Description changes size. This works
+ * pretty well on all browsers except IE 8.
+ */
+#Create #field_container_component { width: 1px; }
+#Create #field_container_reporter  { width: 100%; }
+
+#Create .comment {
+    vertical-align: top;
+    overflow: auto;
+    color: green;
+}
+#Create #comp_desc_container td { padding: 0; }
+#Create #comp_desc { height: 11ex; }
+#Create #os_guess_note {
+    padding-top: 0;
+}
+#Create #os_guess_note div {
+    max-width: 35em;
+}
+
+/* The Possible Duplicates table on enter_bug. */
+#possible_duplicates th {
+    text-align: center; 
+    background: none;
+    border-collapse: collapse;
+}
+/* Make the Add Me to CC button never wrap. */
+#possible_duplicates .yui-dt-col-update_token { white-space: nowrap; }
diff --git a/skins/standard/global.css b/skins/standard/global.css
index 0f64fcab4..5cc71ef53 100644
--- a/skins/standard/global.css
+++ b/skins/standard/global.css
@@ -504,45 +504,6 @@ input.required, select.required, span.required_explanation {
     list-style-type: none;
 }
 
-/*************/
-/* enter_bug */
-/*************/
-
-form#Create table {
-    border-spacing: 0;
-    border-width: 0;
-}
-form#Create td, form#Create th {
-    padding: .25em;
-}
-form#Create th {
-    text-align: right;
-}
-
-/* This makes the "component" column as small as possible (since it
- * contains only fixed-width content) and the Reporter column
- * as large as possible, which makes the form not jump around
- * when the Component Description changes size. This works
- * pretty well on all browsers except IE 8.
- */
-form#Create #field_container_component { width: 1px; }
-form#Create #field_container_reporter  { width: 100%; }
-
-form#Create .comment {
-    vertical-align: top;
-    overflow: auto;
-    color: green;
-}
-form#Create #comp_desc_container td { padding: 0; }
-form#Create #comp_desc { height: 11ex; }
-form#Create #os_guess_note {
-    padding-top: 0;
-}
-form#Create #os_guess_note div {
-    max-width: 35em;
-}
-
-
 .image_button {
     background-repeat: no-repeat;
     background-position: center center;
diff --git a/template/en/default/bug/create/create.html.tmpl b/template/en/default/bug/create/create.html.tmpl
index a59fe9112..0733de02a 100644
--- a/template/en/default/bug/create/create.html.tmpl
+++ b/template/en/default/bug/create/create.html.tmpl
@@ -30,10 +30,11 @@
 
 [% PROCESS global/header.html.tmpl
   title = title
-  yui = [ 'autocomplete', 'calendar' ]
-  style_urls = [ 'skins/standard/attachment.css' ]
+  yui = [ 'autocomplete', 'calendar', 'datatable' ]
+  style_urls = [ 'skins/standard/attachment.css',
+                 'skins/standard/enter_bug.css' ]
   javascript_urls = [ "js/attachment.js", "js/util.js",
-                      "js/field.js", "js/TUI.js" ]
+                      "js/field.js", "js/TUI.js", "js/bug.js" ]
   onload = 'set_assign_to();'
 %]
 
@@ -169,7 +170,7 @@ TUI_hide_default('expert_fields');
 </script>
 
 <form name="Create" id="Create" method="post" action="post_bug.cgi"
-      enctype="multipart/form-data">
+      class="enter_bug_form" enctype="multipart/form-data">
 <input type="hidden" name="product" value="[% product.name FILTER html %]">
 <input type="hidden" name="token" value="[% token FILTER html %]">
 
@@ -508,13 +509,48 @@ TUI_hide_default('expert_fields');
     <td colspan="3">
       <input name="short_desc" size="70" value="[% short_desc FILTER html %]"
              maxlength="255" spellcheck="true" aria-required="true"
-             class="required">
+             class="required" id="short_desc">
     </td>
   </tr>
 
+  [% IF feature_enabled('jsonrpc') AND !cloned_bug_id %]
+    <tr id="possible_duplicates_container" class="bz_default_hidden">
+      <th>Possible<br>Duplicates:</th>
+      <td colspan="3">
+        <div id="possible_duplicates"></div>
+        <script type="text/javascript">
+          var dt_columns = [ 
+              { key: "id", label: "[% field_descs.bug_id FILTER js %]",
+                formatter: YAHOO.bugzilla.dupTable.formatBugLink },
+              { key: "summary", 
+                label: "[% field_descs.short_desc FILTER js %]" },
+              { key: "status",
+                label: "[% field_descs.bug_status FILTER js %]",
+                formatter: YAHOO.bugzilla.dupTable.formatStatus },
+              { key: "update_token", label: '',
+                formatter: YAHOO.bugzilla.dupTable.formatCcButton }
+          ];
+          YAHOO.bugzilla.dupTable.addCcMessage = "Add Me to the CC List";
+          YAHOO.bugzilla.dupTable.init({
+            container: 'possible_duplicates',
+            columns: dt_columns,
+            product_name: '[% product.name FILTER js %]',
+            summary_field: 'short_desc',
+            options: {
+              MSG_LOADING: 'Searching for possible duplicates...',
+              MSG_EMPTY:   'No possible duplicates found.',
+              SUMMARY:     'Possible Duplicates'
+            },
+          });
+        </script>
+      </td>
+    </tr>
+  [% END %]
+
   <tr>
     <th>Description:</th>
     <td colspan="3">
+
       [% defaultcontent = BLOCK %]
         [% IF cloned_bug_id %]
 +++ This [% terms.bug %] was initially created as a clone of [% terms.Bug %] #[% cloned_bug_id %] +++
diff --git a/template/en/default/global/header.html.tmpl b/template/en/default/global/header.html.tmpl
index 3d7fc2e68..75fa71825 100644
--- a/template/en/default/global/header.html.tmpl
+++ b/template/en/default/global/header.html.tmpl
@@ -52,6 +52,7 @@
 [% SET yui_css = {
   autocomplete => 1,
   calendar     => 1,
+  datatable    => 1,
 } %]
 
 [%# Note: This is simple dependency resolution--you can't have dependencies
@@ -60,6 +61,7 @@
   #%]
 [% SET yui_deps = {
   autocomplete => ['json', 'connection', 'datasource'],
+  datatable    => ['json', 'connection', 'datasource', 'element'],
 } %]
 
 
@@ -99,7 +101,20 @@
     [% END %]
     [% style_urls.unshift('skins/standard/global.css') %]
 
+    [%# YUI dependency resolution %]
+    [%# We have to do this in a separate array, because modifying the
+      # existing array by unshift'ing dependencies confuses FOREACH.
+      #%]
+    [% SET yui_resolved = [] %]
+    [% FOREACH yui_name = yui %]
+      [% FOREACH yui_dep = yui_deps.${yui_name}.reverse %]
+        [% yui_resolved.push(yui_dep) IF NOT yui_resolved.contains(yui_dep) %]
+      [% END %]
+      [% yui_resolved.push(yui_name) IF NOT yui_resolved.contains(yui_name) %]
+    [% END %]
+    [% SET yui = yui_resolved %]
 
+    [%# YUI CSS %]
     [% FOREACH yui_name = yui %]
       [% IF yui_css.$yui_name %]
         <link rel="stylesheet" type="text/css"
@@ -218,12 +233,6 @@
     <script src="js/yui/yahoo-dom-event/yahoo-dom-event.js"
             type="text/javascript"></script>
     <script src="js/yui/cookie/cookie-min.js" type="text/javascript"></script>
-    [%# Resolve YUI dependencies. Note that CSS was already done above. %]
-    [% FOREACH yui_name = yui %]
-      [% IF yui_deps.$yui_name %]
-         [% yui = yui_deps.${yui_name}.merge(yui) %]
-      [% END %]
-    [% END %]
     [% FOREACH yui_name = yui %]
       <script type="text/javascript" 
               src="js/yui/[% yui_name FILTER html %]/