Specify new Git-LFS-over-HTTP behavior

Changes to `GitHttpClientController`’s authentication logic caused this behavior change.

The old 401 Unauthorized statuses didn’t cause any harm, but they weren’t quite as accurate as the new behavior.

spec/requests/lfs_http_spec.rb

@@ -759,8 +759,8 @@ describe 'Git LFS API and storage' do
             context 'tries to push to own project' do
               let(:build) { create(:ci_build, :running, pipeline: pipeline, user: user) }
 
-              it 'responds with 401' do
-                expect(response).to have_http_status(401)
+              it 'responds with 403 (not 404 because project is public)' do
+                expect(response).to have_http_status(403)
               end
             end
 
@@ -769,8 +769,9 @@ describe 'Git LFS API and storage' do
               let(:pipeline) { create(:ci_empty_pipeline, project: other_project) }
               let(:build) { create(:ci_build, :running, pipeline: pipeline, user: user) }
 
-              it 'responds with 401' do
-                expect(response).to have_http_status(401)
+              # I'm not sure what this tests that is different from the previous test
+              it 'responds with 403 (not 404 because project is public)' do
+                expect(response).to have_http_status(403)
               end
             end
           end
@@ -778,8 +779,8 @@ describe 'Git LFS API and storage' do
           context 'does not have user' do
             let(:build) { create(:ci_build, :running, pipeline: pipeline) }
 
-            it 'responds with 401' do
-              expect(response).to have_http_status(401)
+            it 'responds with 403 (not 404 because project is public)' do
+              expect(response).to have_http_status(403)
             end
           end
         end
@@ -979,8 +980,8 @@ describe 'Git LFS API and storage' do
               put_authorize
             end
 
-            it 'responds with 401' do
-              expect(response).to have_http_status(401)
+            it 'responds with 403 (not 404 because the build user can read the project)' do
+              expect(response).to have_http_status(403)
             end
           end
 
@@ -993,8 +994,8 @@ describe 'Git LFS API and storage' do
               put_authorize
             end
 
-            it 'responds with 401' do
-              expect(response).to have_http_status(401)
+            it 'responds with 404 (do not leak non-public project existence)' do
+              expect(response).to have_http_status(404)
             end
           end
         end
@@ -1006,8 +1007,8 @@ describe 'Git LFS API and storage' do
             put_authorize
           end
 
-          it 'responds with 401' do
-            expect(response).to have_http_status(401)
+          it 'responds with 404 (do not leak non-public project existence)' do
+            expect(response).to have_http_status(404)
           end
         end
       end
@@ -1079,8 +1080,8 @@ describe 'Git LFS API and storage' do
           context 'tries to push to own project' do
             let(:build) { create(:ci_build, :running, pipeline: pipeline, user: user) }
 
-            it 'responds with 401' do
-              expect(response).to have_http_status(401)
+            it 'responds with 403 (not 404 because project is public)' do
+              expect(response).to have_http_status(403)
             end
           end
 
@@ -1089,8 +1090,9 @@ describe 'Git LFS API and storage' do
             let(:pipeline) { create(:ci_empty_pipeline, project: other_project) }
             let(:build) { create(:ci_build, :running, pipeline: pipeline, user: user) }
 
-            it 'responds with 401' do
-              expect(response).to have_http_status(401)
+            # I'm not sure what this tests that is different from the previous test
+            it 'responds with 403 (not 404 because project is public)' do
+              expect(response).to have_http_status(403)
             end
           end
         end
@@ -1098,8 +1100,8 @@ describe 'Git LFS API and storage' do
         context 'does not have user' do
           let(:build) { create(:ci_build, :running, pipeline: pipeline) }
 
-          it 'responds with 401' do
-            expect(response).to have_http_status(401)
+          it 'responds with 403 (not 404 because project is public)' do
+            expect(response).to have_http_status(403)
           end
         end
       end