Pass tag SHA to post-receive hook when tag is created via UI

We only know the tag SHA after we create the tag.
This means that we pass a different value to the hooks that happen before
creating the tag, and a different value to the hooks that happen after
creating the tag.

This is not an ideal situation, but it is a trade-off we decided to
make. For discussion of the alternatives please refer to
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7700#note_18982873

"pre-receive" and "update" hooks always get the SHA of the commit
that the tag points to. "post-receive" gets the tag SHA if it is
an annotated tag or the commit SHA if it is an lightweight tag.
Currently we always create annotated tags if UI is used.

app/models/repository.rb

@@ -196,8 +196,9 @@ class Repository
 
     options = { message: message, tagger: user_to_committer(user) } if message
 
-    GitHooksService.new.execute(user, path_to_repo, oldrev, target, ref) do
-      rugged.tags.create(tag_name, target, options)
+    GitHooksService.new.execute(user, path_to_repo, oldrev, target, ref) do |service|
+      raw_tag = rugged.tags.create(tag_name, target, options)
+      service.newrev = raw_tag.target_id
     end
 
     find_tag(tag_name)

app/services/git_hooks_service.rb

 class GitHooksService
   PreReceiveError = Class.new(StandardError)
 
+  attr_accessor :oldrev, :newrev, :ref
+
   def execute(user, repo_path, oldrev, newrev, ref)
     @repo_path  = repo_path
     @user       = Gitlab::GlId.gl_id(user)
@@ -16,7 +18,7 @@ class GitHooksService
       end
     end
 
-    yield
+    yield self
 
     run_hook('post-receive')
   end
@@ -25,6 +27,6 @@ class GitHooksService
 
   def run_hook(name)
     hook = Gitlab::Git::Hook.new(name, @repo_path)
-    hook.trigger(@user, @oldrev, @newrev, @ref)
+    hook.trigger(@user, oldrev, newrev, ref)
   end
 end

changelogs/unreleased/24813-project-members-with-developer-access-can-no-longer-create-tags.yml

+---
+title: Pass tag SHA to post-receive hook when tag is created via UI
+merge_request: 7700
+author:

spec/models/repository_spec.rb

@@ -1308,6 +1308,32 @@ describe Repository, models: true do
 
         expect(tag).to be_a(Gitlab::Git::Tag)
       end
+
+      it 'passes commit SHA to pre-receive and update hooks,\
+        and tag SHA to post-receive hook' do
+        pre_receive_hook = Gitlab::Git::Hook.new('pre-receive', repository.path_to_repo)
+        update_hook = Gitlab::Git::Hook.new('update', repository.path_to_repo)
+        post_receive_hook = Gitlab::Git::Hook.new('post-receive', repository.path_to_repo)
+
+        allow(Gitlab::Git::Hook).to receive(:new).
+          and_return(pre_receive_hook, update_hook, post_receive_hook)
+
+        allow(pre_receive_hook).to receive(:trigger).and_call_original
+        allow(update_hook).to receive(:trigger).and_call_original
+        allow(post_receive_hook).to receive(:trigger).and_call_original
+
+        tag = repository.add_tag(user, '8.5', 'master', 'foo')
+
+        commit_sha = repository.commit('master').id
+        tag_sha = tag.target
+
+        expect(pre_receive_hook).to have_received(:trigger).
+          with(anything, anything, commit_sha, anything)
+        expect(update_hook).to have_received(:trigger).
+          with(anything, anything, commit_sha, anything)
+        expect(post_receive_hook).to have_received(:trigger).
+          with(anything, anything, tag_sha, anything)
+      end
     end
 
     context 'with an invalid target' do