diff --git a/modules/simpletest/tests/upgrade/drupal-6.upload.database.php b/modules/simpletest/tests/upgrade/drupal-6.upload.database.php
index 46ebe2c..7315f55 100644
--- a/modules/simpletest/tests/upgrade/drupal-6.upload.database.php
+++ b/modules/simpletest/tests/upgrade/drupal-6.upload.database.php
@@ -127,6 +127,48 @@ db_insert('files')->fields(array(
   'status' => '1',
   'timestamp' => '1285708958',
 ))
+// On some Drupal 6 sites, more than one file can have the same filepath. See
+// https://www.drupal.org/node/1260938.
+->values(array(
+  'fid' => '12',
+  'uid' => '1',
+  'filename' => 'duplicate-name.png',
+  'filepath' => 'sites/default/files/duplicate-name.png',
+  'filemime' => 'image/png',
+  'filesize' => '314',
+  'status' => '1',
+  'timestamp' => '1285708958',
+))
+->values(array(
+  'fid' => '13',
+  'uid' => '1',
+  'filename' => 'duplicate-name.png',
+  'filepath' => 'sites/default/files/duplicate-name.png',
+  'filemime' => 'image/png',
+  'filesize' => '314',
+  'status' => '1',
+  'timestamp' => '1285708958',
+))
+->values(array(
+  'fid' => '14',
+  'uid' => '1',
+  'filename' => 'duplicate-name.png',
+  'filepath' => 'sites/default/files/duplicate-name.png',
+  'filemime' => 'image/png',
+  'filesize' => '314',
+  'status' => '1',
+  'timestamp' => '1285708958',
+))
+->values(array(
+  'fid' => '15',
+  'uid' => '1',
+  'filename' => 'duplicate-name.png',
+  'filepath' => 'sites/default/files/duplicate-name.png',
+  'filemime' => 'image/png',
+  'filesize' => '314',
+  'status' => '1',
+  'timestamp' => '1285708958',
+))
 ->execute();
 
 db_insert('node')->fields(array(
@@ -197,6 +239,23 @@ db_insert('node')->fields(array(
   'tnid' => '0',
   'translate' => '0',
 ))
+->values(array(
+  'nid' => '41',
+  'vid' => '55',
+  'type' => 'page',
+  'language' => '',
+  'title' => 'node title 41 revision 55',
+  'uid' => '1',
+  'status' => '1',
+  'created' => '1285709012',
+  'changed' => '1285709012',
+  'comment' => '0',
+  'promote' => '0',
+  'moderate' => '0',
+  'sticky' => '0',
+  'tnid' => '0',
+  'translate' => '0',
+))
  ->execute();
 
 db_insert('node_revisions')->fields(array(
@@ -254,6 +313,28 @@ db_insert('node_revisions')->fields(array(
   'timestamp' => '1285709012',
   'format' => '1',
 ))
+->values(array(
+  'nid' => '41',
+  'vid' => '54',
+  'uid' => '1',
+  'title' => 'node title 41 revision 54',
+  'body' => "Attachments:\r\nduplicate-name.png",
+  'teaser' => "Attachments:\r\nduplicate-name.png",
+  'log' => '',
+  'timestamp' => '1285709012',
+  'format' => '1',
+))
+->values(array(
+  'nid' => '41',
+  'vid' => '55',
+  'uid' => '1',
+  'title' => 'node title 41 revision 55',
+  'body' => "Attachments:\r\nduplicate-name.png\r\nduplicate-name.png\r\nduplicate-name.png",
+  'teaser' => "Attachments:\r\nduplicate-name.png\r\nduplicate-name.png\r\nduplicate-name.png",
+  'log' => '',
+  'timestamp' => '1285709012',
+  'format' => '1',
+))
  ->execute();
 
 db_create_table('upload', array(
@@ -415,6 +496,38 @@ db_insert('upload')->fields(array(
   'list' => '1',
   'weight' => '0',
 ))
+->values(array(
+  'fid' => '12',
+  'nid' => '41',
+  'vid' => '54',
+  'description' => 'duplicate-name.png',
+  'list' => '1',
+  'weight' => '0',
+))
+->values(array(
+  'fid' => '13',
+  'nid' => '41',
+  'vid' => '55',
+  'description' => 'duplicate-name-hidden.png',
+  'list' => '0',
+  'weight' => '0',
+))
+->values(array(
+  'fid' => '14',
+  'nid' => '41',
+  'vid' => '55',
+  'description' => 'duplicate-name-shown-1.png',
+  'list' => '1',
+  'weight' => '0',
+))
+->values(array(
+  'fid' => '15',
+  'nid' => '41',
+  'vid' => '55',
+  'description' => 'duplicate-name-shown-2.png',
+  'list' => '1',
+  'weight' => '0',
+))
 ->execute();
 
 // Add series of entries for invalid node vids to the {upload} table.
@@ -431,7 +544,7 @@ for ($i = 30; $i < 250; $i += 2) {
   ->values(array(
     'fid' => $i,
     'nid' => '40',
-    'vid' => 24 + $i,
+    'vid' => 26 + $i,
     'description' => 'crazy-basename.png',
     'list' => '1',
     'weight' => '0',
@@ -440,7 +553,7 @@ for ($i = 30; $i < 250; $i += 2) {
   ->values(array(
     'fid' => 2,
     'nid' => '40',
-    'vid' => 24 + $i + 1,
+    'vid' => 26 + $i + 1,
     'description' => 'crazy-basename.png',
     'list' => '1',
     'weight' => '0',
diff --git a/modules/simpletest/tests/upgrade/upgrade.upload.test b/modules/simpletest/tests/upgrade/upgrade.upload.test
index be352bd..211ed0a 100644
--- a/modules/simpletest/tests/upgrade/upgrade.upload.test
+++ b/modules/simpletest/tests/upgrade/upgrade.upload.test
@@ -64,12 +64,28 @@ class UploadUpgradePathTestCase extends UpgradePathTestCase {
       }
       $this->assertIdentical($filenames, $recorded_filenames, 'The uploaded files are present in the same order after the upgrade.');
     }
+
     // Test for the file with repeating basename to only have the streaming
     // path replaced.
     $node = node_load(40, 53);
     $repeated_basename_file = $node->upload[LANGUAGE_NONE][4];
     $this->assertEqual($repeated_basename_file['uri'], 'private://drupal-6/file/directory/path/crazy-basename.png', "The file with the repeated basename path only had the stream portion replaced");
 
+    // Ensure that duplicate filepaths are reduced.
+    $node0 = node_load(41, 54);
+    $node1 = node_load(41, 55);
+    // Ensure that both revisions point to the same file ID.
+    $items0 = field_get_items('node', $node0, 'upload');
+    $this->assertEqual(count($items0), 1);
+    $items1 = field_get_items('node', $node1, 'upload');
+    $this->assertEqual(count($items1), 1);
+    $this->assertEqual($items0[0]['fid'], $items1[0]['fid']);
+    // The revision with more than one reference to the same file should retain
+    // the first reference that isn't hidden.
+    $this->assertEqual($items1[0]['description'], 'duplicate-name-shown-1.png');
+    // No duplicate files should remain on the Drupal 7 site.
+    $this->assertEqual(0, db_query("SELECT COUNT(*) FROM {file_managed} GROUP BY uri HAVING COUNT(fid) > 1")->fetchField());
+
     // Make sure the file settings were properly migrated.
     $d6_file_directory_temp = '/drupal-6/file/directory/temp';
     $d6_file_directory_path = '/drupal-6/file/directory/path';
diff --git a/modules/system/system.install b/modules/system/system.install
index 64c989a..e29df54 100644
--- a/modules/system/system.install
+++ b/modules/system/system.install
@@ -2806,12 +2806,72 @@ function system_update_7061(&$sandbox) {
     // Initialize batch update information.
     $sandbox['progress'] = 0;
     $sandbox['last_vid_processed'] = -1;
-    $sandbox['max'] = db_query("SELECT COUNT(*) FROM {system_update_7061}")->fetchField();
+    $sandbox['max'] = db_query("SELECT COUNT(*) FROM {system_update_7061}")->fetchField()
+       + db_query('SELECT COUNT(*) FROM {files}')->fetchField();
+
+    // There is a chance that we have multiple file entries pointing to the same
+    // physical file, see https://www.drupal.org/node/1260938.
+    // Create batch requests to update those files, by deduplicating them
+    // and point to the first of the possible file IDs.
+    $sandbox['last_fid_processed'] = -1;
+
+    // Therefore create a mapping table between old and new FIDs.
+    if (!db_table_exists('system_update_7061_fid_mapping')) {
+      $table = array(
+        'fields' => array(
+          'old_fid' => array('type' => 'int'),
+          'new_fid' => array('type' => 'int'),
+        ),
+        'primary key' => array('old_fid'),
+      );
+      db_create_table('system_update_7061_fid_mapping', $table);
+    }
+  }
+
+  $limit = variable_get('upload_update_batch_size', 100);
+
+  $fid_filepath = db_query_range('SELECT fid, filepath FROM {files} WHERE fid > :lastfid ORDER BY FID ASC', 0, $limit, array(':lastfid' => $sandbox['last_fid_processed']))
+    ->fetchAll();
+  if (!empty($fid_filepath)) {
+    foreach ($fid_filepath as $row) {
+      // Check whether for the filepath of this particular file we have
+      // duplicate entries.
+      $duplicate_fids = db_query('SELECT fid FROM {files} WHERE filepath = :filepath ORDER BY fid ASC', array(':filepath' => $row->filepath))
+        ->fetchCol();
+
+      // Detect whether we have duplicates.
+      if (count($duplicate_fids) > 1) {
+        // In case we have duplicate FIDs for a given filepath, keep just the first
+        // one.
+        $kept_fid = array_shift($duplicate_fids);
+        db_delete('files')
+          ->condition('fid', $duplicate_fids, 'IN')
+          ->execute();
+        db_update('upload')
+          ->fields(array('fid' => $kept_fid))
+          ->condition('fid', $duplicate_fids, 'IN')
+          ->execute();
+
+        $insert = db_insert('system_update_7061_fid_mapping')
+          ->fields(array('old_fid', 'new_fid'));
+        foreach ($duplicate_fids as $fid) {
+          $insert->values(array('old_fid' => $fid, 'new_fid' => $kept_fid));
+        }
+        $insert->execute();
+      }
+
+      $sandbox['last_fid_processed'] = $row->fid;
+      $sandbox['progress']++;
+    }
+
+    // In case we update still files we skip the other part of the update
+    // function.
+    $sandbox['#finished'] = $sandbox['progress'] / $sandbox['max'];
+    return;
   }
 
   // Determine vids for this batch.
   // Process all files attached to a given revision during the same batch.
-  $limit = variable_get('upload_update_batch_size', 100);
   $vids = db_query_range('SELECT vid FROM {system_update_7061} WHERE vid > :lastvid ORDER BY vid', 0, $limit, array(':lastvid' => $sandbox['last_vid_processed']))
     ->fetchCol();