Display full pre-receive and post-receive hook output in GitLab UI

changelogs/unreleased/fix-multi-line-hook-output.yml

+---
+title: Display full pre-receive and post-receive hook output in GitLab UI
+merge_request: 14222
+author: Robin Bobbitt
+type: fixed

lib/gitlab/git/hook.rb

@@ -83,13 +83,14 @@ module Gitlab
       def call_update_hook(gl_id, oldrev, newrev, ref)
         Dir.chdir(repo_path) do
           stdout, stderr, status = Open3.capture3({ 'GL_ID' => gl_id }, path, ref, oldrev, newrev)
-          [status.success?, stderr.presence || stdout]
+          [status.success?, (stderr.presence || stdout).gsub(/\R/, "<br>").html_safe]
         end
       end
 
       def retrieve_error_message(stderr, stdout)
-        err_message = stderr.gets
-        err_message.blank? ? stdout.gets : err_message
+        err_message = stderr.read
+        err_message = err_message.blank? ? stdout.read : err_message
+        err_message.gsub(/\R/, "<br>").html_safe
       end
     end
   end

spec/lib/gitlab/git/hook_spec.rb

@@ -28,6 +28,7 @@ describe Gitlab::Git::Hook do
         f.write(<<-HOOK)
           echo 'regular message from the hook'
           echo 'error message from the hook' 1>&2
+          echo 'error message from the hook line 2' 1>&2
           exit 1
         HOOK
       end
@@ -73,7 +74,7 @@ describe Gitlab::Git::Hook do
 
             status, errors = hook.trigger(gl_id, blank, blank, ref)
             expect(status).to be false
-            expect(errors).to eq("error message from the hook\n")
+            expect(errors).to eq("error message from the hook<br>error message from the hook line 2<br>")
           end
         end
       end