pull-requests: add link to switch base based on the target.

rhodecode/model/pull_request.py

@@ -1320,6 +1320,7 b' class PullRequestModel(BaseModel):'
 
     def generate_repo_data(self, repo, commit_id=None, branch=None,
                            bookmark=None, translator=None):
+        from rhodecode.model.repo import RepoModel
 
         all_refs, selected_ref = \
             self._get_repo_pullrequest_sources(
@@ -1339,6 +1340,8 b' class PullRequestModel(BaseModel):'
                 'lastname': repo.user.last_name,
                 'gravatar_link': h.gravatar_url(repo.user.email, 14),
             },
+            'name': repo.repo_name,
+            'link': RepoModel().get_url(repo),
             'description': h.chop_at_smart(repo.description_safe, '\n'),
             'refs': {
                 'all_refs': all_refs,

rhodecode/templates/pullrequests/pullrequest.mako

@@ -427,8 +427,9 b''
 
   var targetRepoChanged = function(repoData) {
       // generate new DESC of target repo displayed next to select
+      var prLink = pyroutes.url('pullrequest_new', {'repo_name': repoData['name']});
       $('#target_repo_desc').html(
-          "<strong>${_('Target repository')}</strong>: {0}".format(repoData['description'])
+          "<strong>${_('Target repository')}</strong>: {0}. <a href=\"{1}\">Use as source</a>".format(repoData['description'], prLink)
       );
 
       // generate dynamic select2 for refs.