Fix a bug with trailing slash in teamcity_url

See https://gitlab.com/gitlab-org/gitlab-ce/issues/3515

CHANGELOG

@@ -123,6 +123,9 @@ v 8.6.0
   - Add information about `image` and `services` field at `job` level in the `.gitlab-ci.yml` documentation (Pat Turner)
   - HTTP error pages work independently from location and config (Artem Sidorenko)
   - Update `omniauth-saml` to 1.5.0 to allow for custom response attributes to be set
+  - Fix avatar stretching by providing a cropping feature (Johann Pardanaud)
+  - Fix a bug whith trailing slash in teamcity_url (Charles May)
+  - Don't load all of GitLab in mail_room
   - Memoize @group in Admin::GroupsController (Yatish Mehta)
   - Indicate how much an MR diverged from the target branch (Pierre de La Morinerie)
   - Added omniauth-auth0 Gem (Daniel Carraro)

app/models/project_services/teamcity_service.rb

@@ -85,13 +85,15 @@ class TeamcityService < CiService
   end
 
   def build_info(sha)
-    url = URI.parse("#{teamcity_url}/httpAuth/app/rest/builds/"\
-                    "branch:unspecified:any,number:#{sha}")
+    url = URI.join(
+      teamcity_url,
+      "/httpAuth/app/rest/builds/branch:unspecified:any,number:#{sha}"
+    ).to_s
     auth = {
       username: username,
       password: password,
     }
-    @response = HTTParty.get("#{url}", verify: false, basic_auth: auth)
+    @response = HTTParty.get(url, verify: false, basic_auth: auth)
   end
 
   def build_page(sha, ref)
@@ -100,12 +102,14 @@ class TeamcityService < CiService
     if @response.code != 200
       # If actual build link can't be determined,
       # send user to build summary page.
-      "#{teamcity_url}/viewLog.html?buildTypeId=#{build_type}"
+      URI.join(teamcity_url, "/viewLog.html?buildTypeId=#{build_type}").to_s
     else
       # If actual build link is available, go to build result page.
       built_id = @response['build']['id']
-      "#{teamcity_url}/viewLog.html?buildId=#{built_id}"\
-      "&buildTypeId=#{build_type}"
+      URI.join(
+        teamcity_url,
+        "#{teamcity_url}/viewLog.html?buildId=#{built_id}&buildTypeId=#{build_type}"
+      ).to_s
     end
   end
 
@@ -140,7 +144,8 @@ class TeamcityService < CiService
 
     branch = Gitlab::Git.ref_name(data[:ref])
 
-    self.class.post("#{teamcity_url}/httpAuth/app/rest/buildQueue",
+    self.class.post(
+      URI.join(teamcity_url, "/httpAuth/app/rest/buildQueue").to_s,
       body: "<build branchName=\"#{branch}\">"\
             "<buildType id=\"#{build_type}\"/>"\
             '</build>',