diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 2c0b7635a..07348cd61 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -541,7 +541,7 @@ class Attachment < ApplicationRecord
     just_filename = value.gsub(/\A.*(\\|\/)/m, '')
 
     # Finally, replace invalid characters with underscore
-    just_filename.gsub(/[\/\?\%\*\:\|\"\'<>\n\r]+/, '_')
+    just_filename.gsub(/[\/?%*:|"'<>\n\r]+/, '_')
   end
 
   # Returns the subdirectory in which the attachment will be saved
@@ -556,7 +556,7 @@ class Attachment < ApplicationRecord
     def create_diskfile(filename, directory=nil, &)
       timestamp = DateTime.now.strftime("%y%m%d%H%M%S")
       ascii = ''
-      if %r{^[a-zA-Z0-9_\.\-]*$}.match?(filename) && filename.length <= 50
+      if %r{^[a-zA-Z0-9_.-]*$}.match?(filename) && filename.length <= 50
         ascii = filename
       else
         ascii = ActiveSupport::Digest.hexdigest(filename)
diff --git a/app/models/changeset.rb b/app/models/changeset.rb
index 40e6cf51c..a9838fd11 100644
--- a/app/models/changeset.rb
+++ b/app/models/changeset.rb
@@ -117,7 +117,7 @@ class Changeset < ApplicationRecord
     |
     (\d+):(\d+)
     |
-    (\d+([\.,]\d+)?)h?
+    (\d+([.,]\d+)?)h?
     )
     /x
 
@@ -135,7 +135,7 @@ class Changeset < ApplicationRecord
     referenced_issues = []
     regexp =
       %r{
-        ([\s\(\[,-]|^)((#{kw_regexp})[\s:]+)?
+        ([\s(\[,-]|^)((#{kw_regexp})[\s:]+)?
         (\#\d+(\s+@#{TIMELOG_RE})?([\s,;&]+\#\d+(\s+@#{TIMELOG_RE})?)*)
         (?=[[:punct:]]|\s|<|$)
       }xi
diff --git a/app/models/user.rb b/app/models/user.rb
index f41f654e1..124755775 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -122,7 +122,7 @@ class User < Principal
   validates_presence_of :login, :firstname, :lastname, :if => Proc.new {|user| !user.is_a?(AnonymousUser)}
   validates_uniqueness_of :login, :if => Proc.new {|user| user.login_changed? && user.login.present?}, :case_sensitive => false
   # Login must contain letters, numbers, underscores only
-  validates_format_of :login, :with => /\A[a-z0-9_\-@\.]*\z/i
+  validates_format_of :login, :with => /\A[a-z0-9_\-@.]*\z/i
   validates_length_of :login, :maximum => LOGIN_LENGTH_LIMIT
   validates_length_of :firstname, :maximum => 30
   validates_length_of :lastname, :maximum => 255
diff --git a/app/models/wiki_page.rb b/app/models/wiki_page.rb
index d76e288d8..3b638085d 100644
--- a/app/models/wiki_page.rb
+++ b/app/models/wiki_page.rb
@@ -52,7 +52,7 @@ class WikiPage < ApplicationRecord
   attr_writer   :deleted_attachment_ids
 
   validates_presence_of :title
-  validates_format_of :title, :with => /\A[^,\.\/\?\;\|\s]*\z/
+  validates_format_of :title, :with => /\A[^,.\/?;|\s]*\z/
   validates_uniqueness_of :title, :scope => :wiki_id, :case_sensitive => false
   validates_length_of :title, maximum: 255
   validates_associated :content
diff --git a/config/routes.rb b/config/routes.rb
index df48e19e9..75e7ea01c 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -297,7 +297,7 @@ Rails.application.routes.draw do
         :controller => 'repositories',
         :action => action,
         :format => 'html',
-        :constraints => {:rev => /[a-z0-9\.\-_]+/, :path => /.*/}
+        :constraints => {:rev => /[a-z0-9.\-_]+/, :path => /.*/}
   end
 
   %w(browse entry raw changes annotate).each do |action|
@@ -311,7 +311,7 @@ Rails.application.routes.draw do
   get "projects/:id/repository/:repository_id/revisions/:rev/diff(/*path)",
       :to => 'repositories#diff',
       :format => 'html',
-      :constraints => {:rev => /[a-z0-9\.\-_]+/, :path => /.*/, :format => /(html|diff)/ }
+      :constraints => {:rev => /[a-z0-9.\-_]+/, :path => /.*/, :format => /(html|diff)/ }
 
   get "projects/:id/repository/:repository_id/diff(/*path)",
       :to => 'repositories#diff',
diff --git a/lib/redmine/scm/adapters/cvs_adapter.rb b/lib/redmine/scm/adapters/cvs_adapter.rb
index 07e882826..50788dab1 100644
--- a/lib/redmine/scm/adapters/cvs_adapter.rb
+++ b/lib/redmine/scm/adapters/cvs_adapter.rb
@@ -317,7 +317,7 @@ module Redmine
           blame = Annotate.new
           scm_cmd(*cmd_args) do |io|
             io.each_line do |line|
-              next unless line =~ %r{^([\d\.]+)\s+\(([^\)]+)\s+[^\)]+\):\s(.*)$}
+              next unless line =~ %r{^([\d.]+)\s+\(([^)]+)\s+[^)]+\):\s(.*)$}
 
               blame.add_line(
                 $3.rstrip,
diff --git a/lib/redmine/scm/adapters/git_adapter.rb b/lib/redmine/scm/adapters/git_adapter.rb
index c7a5c6b66..28c2f7496 100644
--- a/lib/redmine/scm/adapters/git_adapter.rb
+++ b/lib/redmine/scm/adapters/git_adapter.rb
@@ -118,7 +118,7 @@ module Redmine
         end
 
         def entry(path=nil, identifier=nil)
-          parts = path.to_s.split(%r{[\/\\]}).select {|n| !n.blank?}
+          parts = path.to_s.split(%r{[/\\]}).select {|n| !n.blank?}
           search_path = parts[0..-2].join('/')
           search_name = parts[-1]
           if search_path.blank? && search_name.blank?
diff --git a/lib/redmine/scm/adapters/subversion_adapter.rb b/lib/redmine/scm/adapters/subversion_adapter.rb
index c4bb31148..4183f53ca 100644
--- a/lib/redmine/scm/adapters/subversion_adapter.rb
+++ b/lib/redmine/scm/adapters/subversion_adapter.rb
@@ -302,7 +302,7 @@ module Redmine
           base = path.start_with?('/') ? root_url : url
           uri = "#{base}/#{path}"
           uri = Addressable::URI.encode(uri)
-          shell_quote(uri.gsub(/[?<>\*]/, ''))
+          shell_quote(uri.gsub(/[?<>*]/, ''))
         end
       end
     end