[Repo Command] Add ability to add custom commit message when pushing spec

CHANGELOG.md

@@ -8,6 +8,10 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
 
 ##### Enhancements
 
+* Add the ability to add a custom commit message when pushing a spec.
+  [Bart Jacobs](https://github.com/bartjacobs)
+  [#4583](https://github.com/CocoaPods/CocoaPods/issues/4583)
+
 * Added support for `pod env` to print the pod environment without having to crash.  
   [Hemal Shah](https://github.com/hemal)
   [#3660](https://github.com/CocoaPods/CocoaPods/issues/3660)

lib/cocoapods/command/repo/push.rb

+require 'tempfile'
 require 'fileutils'
 require 'active_support/core_ext/string/inflections'
 
@@ -28,6 +29,7 @@ module Pod
              'Multiple sources must be comma-delimited.'],
             ['--local-only', 'Does not perform the step of pushing REPO to its remote'],
             ['--no-private', 'Lint includes checks that apply only to public repos'],
+            ['--message', 'Add custom commit message']
           ].concat(super)
         end
 
@@ -39,6 +41,7 @@ module Pod
           @podspec = argv.shift_argument
           @use_frameworks = !argv.flag?('use-libraries')
           @private = argv.flag?('private', true)
+          @message = argv.flag?('message')
           super
         end
 
@@ -48,6 +51,7 @@ module Pod
         end
 
         def run
+          open_editor if @message
           check_if_master_repo
           validate_podspec_files
           check_repo_status
@@ -65,6 +69,21 @@ module Pod
         extend Executable
         executable :git
 
+        # Open default editor to allow users to enter commit message
+        #
+        def open_editor
+          file = Tempfile.new('cocoapods')
+          File.chmod(0777, file.path)
+          file.close
+
+          unless ENV['EDITOR'].nil?
+            system("#{ENV['EDITOR']} #{file.path}")
+            @message = File.read file.path
+          else
+            @message = nil
+          end
+        end
+
         # Temporary check to ensure that users do not push accidentally private
         # specs to the master repo.
         #
@@ -143,7 +162,9 @@ module Pod
           podspec_files.each do |spec_file|
             spec = Pod::Specification.from_file(spec_file)
             output_path = File.join(repo_dir, spec.name, spec.version.to_s)
-            if Pathname.new(output_path).exist?
+            if @message && !@message.empty?
+              message = @message
+            elsif Pathname.new(output_path).exist?
               message = "[Fix] #{spec}"
             elsif Pathname.new(File.join(repo_dir, spec.name)).exist?
               message = "[Update] #{spec}"