Make sure there's only one slash as path separator

In Ruby 2.4, `URI.join("http://test//", "a").to_s` will
remove the double slash, however it's not the case in
Ruby 2.5. Using chomp should work better for the intention,
as we're not trying to allow things like ../ or / paths
resolution.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/53180

5 files changed, 10 insertions, 22 deletions

diff --git a/lib/banzai/filter/absolute_link_filter.rb b/lib/banzai/filter/absolute_link_filter.rb
index 04ec568eee3..a9bdb004c4b 100644
--- a/lib/banzai/filter/absolute_link_filter.rb
+++ b/lib/banzai/filter/absolute_link_filter.rb
@@ -29,6 +29,7 @@ module Banzai
       end
 
       def absolute_link_attr(uri)
+        # Here we really want to expand relative path to absolute path
         URI.join(Gitlab.config.gitlab.url, uri).to_s
       end
     end
diff --git a/lib/bitbucket_server/connection.rb b/lib/bitbucket_server/connection.rb
index 45a437844bd..7efcdcf8619 100644
--- a/lib/bitbucket_server/connection.rb
+++ b/lib/bitbucket_server/connection.rb
@@ -88,35 +88,19 @@ module BitbucketServer
     def build_url(path)
       return path if path.starts_with?(root_url)
 
-      url_join_paths(root_url, path)
+      Gitlab::Utils.append_path(root_url, path)
     end
 
     def root_url
-      url_join_paths(base_uri, "/rest/api/#{api_version}")
+      Gitlab::Utils.append_path(base_uri, "rest/api/#{api_version}")
     end
 
     def delete_url(resource, path)
       if resource == :branches
-        url_join_paths(base_uri, "/rest/branch-utils/#{api_version}#{path}")
+        Gitlab::Utils.append_path(base_uri, "rest/branch-utils/#{api_version}#{path}")
       else
         build_url(path)
       end
     end
-
-    # URI.join is stupid in that slashes are important:
-    #
-    # # URI.join('http://example.com/subpath', 'hello')
-    # => http://example.com/hello
-    #
-    # We really want http://example.com/subpath/hello
-    #
-    def url_join_paths(*paths)
-      paths.map { |path| strip_slashes(path) }.join(SEPARATOR)
-    end
-
-    def strip_slashes(path)
-      path = path[1..-1] if path.starts_with?(SEPARATOR)
-      path.chomp(SEPARATOR)
-    end
   end
 end
diff --git a/lib/gitlab/gon_helper.rb b/lib/gitlab/gon_helper.rb
index 860c39feb64..15137140639 100644
--- a/lib/gitlab/gon_helper.rb
+++ b/lib/gitlab/gon_helper.rb
@@ -8,7 +8,10 @@ module Gitlab
 
     def add_gon_variables
       gon.api_version            = 'v4'
-      gon.default_avatar_url     = URI.join(Gitlab.config.gitlab.url, ActionController::Base.helpers.image_path('no_avatar.png')).to_s
+      gon.default_avatar_url     =
+        Gitlab::Utils.append_path(
+          Gitlab.config.gitlab.url,
+          ActionController::Base.helpers.image_path('no_avatar.png'))
       gon.max_file_size          = Gitlab::CurrentSettings.max_attachment_size
       gon.asset_host             = ActionController::Base.asset_host
       gon.webpack_public_path    = webpack_public_path
diff --git a/lib/gitlab/manifest_import/manifest.rb b/lib/gitlab/manifest_import/manifest.rb
index 4d6034fb956..b69b9ac4b64 100644
--- a/lib/gitlab/manifest_import/manifest.rb
+++ b/lib/gitlab/manifest_import/manifest.rb
@@ -63,7 +63,7 @@ module Gitlab
       end
 
       def repository_url(name)
-        URI.join(remote, name).to_s
+        Gitlab::Utils.append_path(remote, name)
       end
 
       def remote
diff --git a/lib/gitlab/middleware/go.rb b/lib/gitlab/middleware/go.rb
index 1fd8f147b44..6943567fb6d 100644
--- a/lib/gitlab/middleware/go.rb
+++ b/lib/gitlab/middleware/go.rb
@@ -38,7 +38,7 @@ module Gitlab
 
       def go_body(path)
         config = Gitlab.config
-        project_url = URI.join(config.gitlab.url, path)
+        project_url = Gitlab::Utils.append_path(config.gitlab.url, path)
         import_prefix = strip_url(project_url.to_s)
 
         repository_url = if Gitlab::CurrentSettings.enabled_git_access_protocol == 'ssh'