Implement 2 git hooks: tagf removal and commit message

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/views/projects/git_hooks/index.html.haml

@@ -17,13 +17,13 @@
         = f.check_box :deny_delete_tag
         %span.descr Dont allow users to remove git tags
 
-  .form-group
+  -#.form-group
     = f.label :force_push_regex, "Force push", class: 'control-label'
     .col-sm-10
       = f.text_field :force_push_regex, class: "form-control"
       %p.hint Regular expression for branches to allow force push. Empty - allow force push to any branch
 
-  .form-group
+  -#.form-group
     = f.label :delete_branch_regex, "Branch removal", class: 'control-label'
     .col-sm-10
       = f.text_field :delete_branch_regex, class: "form-control"
@@ -32,7 +32,7 @@
   .form-group
     = f.label :commit_message_regex, "Commit message", class: 'control-label'
     .col-sm-10
-      = f.text_field :commit_message_regex, class: "form-control"
+      = f.text_field :commit_message_regex, class: "form-control", placeholder: 'Ex. Fix \d+\..*'
       %p.hint Commit message must match this regular expression to be pushed. Empty - allow remove of any commit message
 
   .form-actions

lib/gitlab/git_access.rb

@@ -48,12 +48,39 @@ module Gitlab
                  else
                    :push_code
                  end
-        user.can?(action, project)
+
+        user.can?(action, project) &&
+          pass_git_hooks?(user, project, ref, oldrev, newrev)
       else
         false
       end
     end
 
+    def pass_git_hooks?(user, project, ref, oldrev, newrev)
+      return true unless project.git_hook
+
+      git_hook = project.git_hook
+
+      # Prevent tag removal
+      if git_hook.deny_delete_tag
+        if project.repository.tag_names.include?(ref) && newrev =~ /0000000/
+          return false
+        end
+      end
+
+      # Check commit messages unless its branch removal
+      if git_hook.commit_message_regex.present? && newrev !~ /00000000/
+        commits = project.repository.commits_between(oldrev, newrev)
+        commits.each do |commit|
+          unless commit.safe_message =~ Regexp.new(git_hook.commit_message_regex)
+            return false
+          end
+        end
+      end
+
+      true
+    end
+
     private
 
     def user_allowed?(user)