Index: lib/redmine/database.rb
===================================================================
--- lib/redmine/database.rb	(revision 17364)
+++ lib/redmine/database.rb	(working copy)
@@ -21,7 +21,7 @@
     class << self
       # Returns true if the database is PostgreSQL
       def postgresql?
-        (ActiveRecord::Base.connection.adapter_name =~ /postgresql/i).present?
+        /postgresql/i.match?(ActiveRecord::Base.connection.adapter_name)
       end
 
       # Returns the PostgreSQL version or nil if another DBMS is used
@@ -46,7 +46,7 @@
 
       # Returns true if the database is MySQL
       def mysql?
-        (ActiveRecord::Base.connection.adapter_name =~ /mysql/i).present?
+        /mysql/i.match?(ActiveRecord::Base.connection.adapter_name)
       end
 
       # Returns a SQL statement for case/accent (if possible) insensitive match
Index: lib/redmine/nested_set/issue_nested_set.rb
===================================================================
--- lib/redmine/nested_set/issue_nested_set.rb	(revision 17364)
+++ lib/redmine/nested_set/issue_nested_set.rb	(working copy)
@@ -149,7 +149,7 @@
       end
 
       def lock_nested_set
-        if self.class.connection.adapter_name =~ /sqlserver/i
+        if /sqlserver/i.match?(self.class.connection.adapter_name)
           lock = "WITH (ROWLOCK HOLDLOCK UPDLOCK)"
           # Custom lock for SQLServer
           # This can be problematic if root_id or parent root_id changes
Index: lib/redmine/nested_set/project_nested_set.rb
===================================================================
--- lib/redmine/nested_set/project_nested_set.rb	(revision 17364)
+++ lib/redmine/nested_set/project_nested_set.rb	(working copy)
@@ -119,7 +119,7 @@
 
       def lock_nested_set
         lock = true
-        if self.class.connection.adapter_name =~ /sqlserver/i
+        if /sqlserver/i.match?(self.class.connection.adapter_name)
           lock = "WITH (ROWLOCK HOLDLOCK UPDLOCK)"
         end
         self.class.order(:id).lock(lock).ids