Fix the "Commits" section of the cycle analytics summary.

- The commit count was capped at 10, due to
  `Gitlab::Git::Repository#log` enforcing a limit, with the default set
  to 10.

- Reimplement a small portion of this `log` function to get just the
  data we need.

app/models/cycle_analytics/summary.rb

@@ -10,15 +10,33 @@ class CycleAnalytics
     end
 
     def commits
-      repository = @project.repository.raw_repository
-
-      if @project.default_branch
-        repository.log(ref: @project.default_branch, after: @from).count
-      end
+      ref = @project.default_branch.presence
+      count_commits_for(ref)
     end
 
     def deploys
       @project.deployments.where("created_at > ?", @from).count
     end
+
+    private
+
+    # Don't use the `Gitlab::Git::Repository#log` method, because it enforces
+    # a limit. Since we need a commit count, we _can't_ enforce a limit, so
+    # the easiest way forward is to replicate the relevant portions of the
+    # `log` function here.
+    def count_commits_for(ref)
+      return unless ref
+
+      repository = @project.repository.raw_repository
+      sha = @project.repository.commit(ref).sha
+
+      cmd = %W(git --git-dir=#{repository.path} log)
+      cmd << '--format=%H'
+      cmd << "--after=#{@from.iso8601}"
+      cmd << sha
+
+      raw_output = IO.popen(cmd) { |io| io.read }
+      raw_output.lines.count
+    end
   end
 end

spec/models/cycle_analytics/summary_spec.rb

@@ -34,6 +34,12 @@ describe CycleAnalytics::Summary, models: true do
 
       expect(subject.commits).to eq(0)
     end
+
+    it "finds a large (> 100) snumber of commits if present" do
+      Timecop.freeze(5.days.from_now) { create_commit("Test message", project, user, 'master', count: 100) }
+
+      expect(subject.commits).to eq(100)
+    end
   end
 
   describe "#deploys" do

spec/support/cycle_analytics_helpers.rb

@@ -4,9 +4,10 @@ module CycleAnalyticsHelpers
     create_commit("Commit for ##{issue.iid}", issue.project, user, branch_name)
   end
 
-  def create_commit(message, project, user, branch_name)
-    filename = random_git_name
+  def create_commit(message, project, user, branch_name, count: 1)
     oldrev = project.repository.commit(branch_name).sha
+    commit_shas = Array.new(count) do |index|
+      filename = random_git_name
 
       options = {
         committer: project.repository.user_to_committer(user),
@@ -18,10 +19,13 @@ module CycleAnalyticsHelpers
       commit_sha = Gitlab::Git::Blob.commit(project.repository, options)
       project.repository.commit(commit_sha)
 
+      commit_sha
+    end
+
     GitPushService.new(project,
                        user,
                        oldrev: oldrev,
-                       newrev: commit_sha,
+                       newrev: commit_shas.last,
                        ref: 'refs/heads/master').execute
   end