[api] support explicit parameter to get a new branch of a package

newinstance=1 is keeping the link target. To be used to instantiate a
new package instance for service packs.

docs/api/api/api.txt

@@ -619,6 +619,7 @@ Parameters:
   target_package: target package name, optional
   noaccess: the new created project will be read protected, bool, optional
   missingok: the target package does not exist
+  newinstance: the target package exists only via project links, but the link should point to given project
   add_repositories: bool, optional, adds repositories base on source project (default for new projects)
   update_path_elements: bool, optional, update all path elements if needed (used repositories depend on each other)
   extend_package_names: bool, optional, extends package and repository names to allow multiple instances of same package

src/api/app/helpers/branch_package.rb

@@ -328,6 +328,11 @@ def determine_details_about_package_to_branch(p)
       end
     end
 
+    if params[:newinstance]
+      # user explicit wants this link target
+      p[:link_target_project] = Project.get_by_name params[:project]
+    end
+
     # set default based on first found package location
     unless @target_project
       @target_project = "home:#{User.current.login}:branches:#{p[:link_target_project].name}"

src/api/test/functional/maintenance_test.rb

@@ -14,6 +14,39 @@ def setup
     Timecop.return
   end
 
+  def test_instantiate_for_service_packs
+    login_tom
+    # add a new package with defined link target
+    put '/source/home:tom:BaseDistro:SP1/_meta',
+          '<project name="home:tom:BaseDistro:SP1" kind="maintenance_release">
+            <title/> <description/>
+            <link project="BaseDistro:Update"/>
+          </project>'
+    assert_response :success
+
+    post '/source/home:tom:BaseDistro:SP1/pack1', :cmd => 'branch', :target_project => 'home:tom:Branch', :missingok => 1
+    assert_response 400
+    # osc catches this error code and is fallingback to newinstance=1
+    assert_xml_tag tag: 'status', attributes: {code: "not_missing"}
+
+    post '/source/home:tom:BaseDistro:SP1/pack1', :cmd => 'branch', :target_project => 'home:tom:Branch', :newinstance => 1
+    assert_response :success
+    assert_xml_tag tag: 'data', attributes: {name: "sourceproject"}, content: "home:tom:BaseDistro:SP1"
+
+    get "/source/home:tom:Branch/pack1/_link"
+    assert_response :success
+    assert_xml_tag tag: 'link', attributes: {project: "home:tom:BaseDistro:SP1"}
+
+    post '/source/BaseDistro:Update/pack1', :cmd => 'branch', :target_project => 'home:tom:Branch', :missingok => 1, :extend_package_names => 1
+    assert_response 400
+    assert_xml_tag tag: 'status', attributes: {code: "not_missing"}
+
+    delete "/source/home:tom:Branch"
+    assert_response :success
+    delete "/source/home:tom:BaseDistro:SP1"
+    assert_response :success
+  end
+
   def test_create_maintenance_project
     login_tom
 

src/api/test/unit/code_quality_test.rb

@@ -72,6 +72,7 @@ def setup
       'BranchPackage#find_packages_to_branch' => 234.73,
       'BranchPackage#create_branch_packages' => 214.0,
       'BranchPackage#check_for_update_project' => 101.04,
+      'BranchPackage#determine_details_about_package_to_branch' => 81.6,
       'BranchPackage#lookup_incident_pkg' => 80.64,
       'BsRequest#change_review_state' => 203.53,
       'BsRequest#changestate_accepted' => 80.21,