includes/database/pgsql/database.inc        |   24 ++++++++++++++++++++
 includes/database/pgsql/query.inc           |   20 ++++++++++++++++
 includes/database/pgsql/schema.inc          |    1 +
 modules/simpletest/tests/database_test.test |   32 +++++++++++++++++++++++++++
 4 files changed, 77 insertions(+), 0 deletions(-)

diff --git includes/database/pgsql/database.inc includes/database/pgsql/database.inc
index dbb3286..f3602d3 100644
--- includes/database/pgsql/database.inc
+++ includes/database/pgsql/database.inc
@@ -188,6 +188,30 @@ class DatabaseConnection_pgsql extends DatabaseConnection {
 
     return $id;
   }
+
+  /**
+   * Overrides PDO::lastInsertId().
+   *
+   * Catchs and handles the exception in case currval() fails.
+   */
+  public function lastInsertId($name = null) {
+    try {
+      return parent::lastInsertId($name);
+    } catch(PDOException $e) {
+      if ($e->getCode() == 55000) {
+        // This fails if a value was inserted into the serial column and
+        // nextval() was never called. In that case, the last_insert_id is known
+        // by the caller and NULL is returned.
+        $last_insert_id = NULL;
+      }
+      else {
+        // If it is a different exception, re-throw it.
+        throw $e;
+      }
+    }
+    return $last_insert_id;
+  }
+
 }
 
 /**
diff --git includes/database/pgsql/query.inc includes/database/pgsql/query.inc
index 8825229..f71e229 100644
--- includes/database/pgsql/query.inc
+++ includes/database/pgsql/query.inc
@@ -69,6 +69,26 @@ class InsertQuery_pgsql extends InsertQuery {
     }
     $last_insert_id = $this->connection->query($stmt, array(), $options);
 
+    // If a value was inserted into a serial column, update the sequence.
+    if (!empty($table_information->serial_fields)) {
+      // If the first serial field is in the insert fields, update the
+      // last_insert_id to that value.
+      $key = array_search($table_information->serial_fields[0], $this->insertFields);
+      if ($key !== FALSE) {
+        $last_insert_id = $insert_values[$key];
+      }
+
+      foreach ($table_information->serial_fields as $index => $serial_field) {
+        if (in_array($serial_field, $this->insertFields)) {
+          // Load the next sequence value and the max value of the table.
+          $new_value = $this->connection->query("SELECT NEXTVAL('" . $table_information->sequences[$index] . "') AS nextval, MAX(" . $serial_field . ") AS max FROM {" . $this->table . "}")->fetchObject();
+          // Set the current sequence value to the bigger of those two values.
+          $curval = $new_value->nextval > $new_value->max ? $new_value->nextval : $new_value->max;
+          $this->connection->query("SELECT SETVAL('" . $table_information->sequences[$index] . "', :curval)", array(':curval' => $curval));
+        }
+      }
+    }
+
     // Re-initialize the values array so that we can re-use this query.
     $this->insertValues = array();
 
diff --git includes/database/pgsql/schema.inc includes/database/pgsql/schema.inc
index cda525b..1b65f5d 100644
--- includes/database/pgsql/schema.inc
+++ includes/database/pgsql/schema.inc
@@ -66,6 +66,7 @@ class DatabaseSchema_pgsql extends DatabaseSchema {
           // return the last insert id. If there is more than 1 sequences the
           // first one (index 0 of the sequences array) will be used.
           $table_information->sequences[] = $matches[1];
+          $table_information->serial_fields[] = $column->column_name;
         }
       }
       $this->tableInformation[$key] = $table_information;
diff --git modules/simpletest/tests/database_test.test modules/simpletest/tests/database_test.test
index 623bcb2..98c5d16 100644
--- modules/simpletest/tests/database_test.test
+++ modules/simpletest/tests/database_test.test
@@ -562,6 +562,38 @@ class DatabaseInsertTestCase extends DatabaseTestCase {
       ->execute();
 
     $this->assertIdentical($id, '5', t('Auto-increment ID returned successfully.'));
+
+    // Test a manual insert.
+    $id = db_insert('test')
+      ->fields(array(
+        'id' => '10',
+        'name' => 'Curly',
+        'age' => '29',
+      ))
+      ->execute();
+
+    debug($id);
+    $this->assertIdentical($id, '10', t('ID returned properly for a manual ID insert.'));
+
+    $id = db_insert('test')
+      ->fields(array(
+        'id' => '7',
+        'name' => 'Sascha',
+        'age' => '24',
+      ))
+      ->execute();
+
+    debug($id);
+    $this->assertIdentical($id, '7', t('ID returned successfully for a manual ID insert smaller than the max value.'));
+
+    $id = db_insert('test')
+      ->fields(array(
+        'name' => 'Peter',
+        'age' => '77',
+      ))
+      ->execute();
+
+    $this->assertTrue($id > 10, t('Auto-increment ID returned successfully after a manual ID was inserted.'));
   }
 
   /**