Allow allow_unrelated_histories option for Base#pull

lib/git/base.rb

@@ -409,14 +409,27 @@ def each_conflict(&block) # :yields: file, your_version, their_version
       self.lib.conflicts(&block)
     end
 
-    # pulls the given branch from the given remote into the current branch
-    #
-    #  @git.pull                          # pulls from origin/master
-    #  @git.pull('upstream')              # pulls from upstream/master
-    #  @git.pull('upstream', 'develope')  # pulls from upstream/develop
-    #
-    def pull(remote = nil, branch = nil)
-      self.lib.pull(remote, branch)
+    # Pulls the given branch from the given remote into the current branch
+    #
+    # @param remote [String] the remote repository to pull from
+    # @param branch [String] the branch to pull from
+    # @param opts [Hash] options to pass to the pull command
+    #
+    # @option opts [Boolean] :allow_unrelated_histories (false) Merges histories of two projects that started their
+    #   lives independently
+    # @example pulls from origin/master
+    #   @git.pull
+    # @example pulls from upstream/master
+    #   @git.pull('upstream')
+    # @example pulls from upstream/develop
+    #   @git.pull('upstream', 'develop')
+    #
+    # @return [Void]
+    #
+    # @raise [Git::FailedError] if the pull fails
+    # @raise [ArgumentError] if a branch is given without a remote
+    def pull(remote = nil, branch = nil, opts = {})
+      self.lib.pull(remote, branch, opts)
     end
 
     # returns an array of Git:Remote objects

lib/git/lib.rb

@@ -1006,10 +1006,11 @@ def push(remote = nil, branch = nil, opts = nil)
       end
     end
 
-    def pull(remote = nil, branch = nil)
+    def pull(remote = nil, branch = nil, opts = {})
       raise ArgumentError, "You must specify a remote if a branch is specified" if remote.nil? && !branch.nil?
 
       arr_opts = []
+      arr_opts << '--allow-unrelated-histories' if opts[:allow_unrelated_histories]
       arr_opts << remote if remote
       arr_opts << branch if branch
       command('pull', *arr_opts)

tests/units/test_pull.rb

@@ -3,7 +3,7 @@
 class TestPull < Test::Unit::TestCase
 
   test 'pull with branch only should raise an ArgumentError' do
-    in_temp_dir do |path|
+    in_temp_dir do
       Dir.mkdir('remote')
 
       Dir.chdir('remote') do
@@ -23,7 +23,7 @@ class TestPull < Test::Unit::TestCase
   end
 
   test 'pull with no args should use the default remote and current branch name' do
-    in_temp_dir do |path|
+    in_temp_dir do
       Dir.mkdir('remote')
 
       Dir.chdir('remote') do
@@ -51,7 +51,7 @@ class TestPull < Test::Unit::TestCase
   end
 
   test 'pull with one arg should use arg as remote and the current branch name' do
-    in_temp_dir do |path|
+    in_temp_dir do
       Dir.mkdir('remote')
 
       Dir.chdir('remote') do
@@ -79,7 +79,7 @@ class TestPull < Test::Unit::TestCase
   end
 
   test 'pull with both remote and branch should use both' do
-    in_temp_dir do |path|
+    in_temp_dir do
       Dir.mkdir('remote')
 
       Dir.chdir('remote') do
@@ -109,4 +109,31 @@ class TestPull < Test::Unit::TestCase
       end
     end
   end
+
+  test 'when pull fails a Git::FailedError should be raised' do
+    in_temp_dir do
+      Dir.mkdir('remote')
+
+      Dir.chdir('remote') do
+        `git init --initial-branch=master`
+        File.write('README.md', 'Line 1')
+        `git add README.md`
+        `git commit -m "Initial commit"`
+      end
+
+      `git clone remote/.git local 2>&1`
+
+      Dir.chdir('local') do
+        git = Git.open('.')
+        assert_raises(Git::FailedError) { git.pull('origin', 'none_existing_branch') }
+      end
+    end
+  end
+
+  test 'pull with allow_unrelated_histories: true' do
+    expected_command_line = ['pull', '--allow-unrelated-histories', 'origin', 'feature1', {}]
+    assert_command_line_eq(expected_command_line) do |git|
+      git.pull('origin', 'feature1', allow_unrelated_histories: true)
+    end
+  end
 end