4 files changed, 59 insertions, 4 deletions
diff --git a/app/assets/stylesheets/pages/issuable.scss b/app/assets/stylesheets/pages/issuable.scss
index 97fab513b01..ad6eb9f6fe0 100644
--- a/app/assets/stylesheets/pages/issuable.scss
+++ b/app/assets/stylesheets/pages/issuable.scss
@@ -6,7 +6,13 @@
 }
 
 .limit-container-width {
-  .detail-page-header {
+  .detail-page-header,
+  .page-content-header,
+  .commit-box,
+  .info-well,
+  .notes,
+  .commit-ci-menu,
+  .files-changed {
     @extend .fixed-width-container;
   }
 
@@ -36,8 +42,7 @@
   }
 
   .diffs {
-    .mr-version-controls,
-    .files-changed {
+    .mr-version-controls {
       @extend .fixed-width-container;
     }
   }
diff --git a/app/views/projects/commit/show.html.haml b/app/views/projects/commit/show.html.haml
index 0d11da2451a..16d2646cb4e 100644
--- a/app/views/projects/commit/show.html.haml
+++ b/app/views/projects/commit/show.html.haml
@@ -1,9 +1,11 @@
 - @no_container = true
+- container_class = !fluid_layout && diff_view == :inline ? 'container-limited' : ''
+- limited_container_width = fluid_layout || diff_view == :inline ? '' : 'limit-container-width'
 - page_title        "#{@commit.title} (#{@commit.short_id})", "Commits"
 - page_description  @commit.description
 = render "projects/commits/head"
 
-%div{ class: container_class }
+.container-fluid{ class: [limited_container_width, container_class] }
   = render "commit_box"
   - if @commit.status
     = render "ci_menu"
diff --git a/changelogs/unreleased/commit-limited-container-width.yml b/changelogs/unreleased/commit-limited-container-width.yml
new file mode 100644
index 00000000000..253646b13da
--- /dev/null
+++ b/changelogs/unreleased/commit-limited-container-width.yml
@@ -0,0 +1,4 @@
+---
+title: Side-by-side view in commits correcly expands full window width
+merge_request:
+author:
diff --git a/spec/views/projects/commit/show.html.haml_spec.rb b/spec/views/projects/commit/show.html.haml_spec.rb
new file mode 100644
index 00000000000..122075cc10e
--- /dev/null
+++ b/spec/views/projects/commit/show.html.haml_spec.rb
@@ -0,0 +1,44 @@
+require 'spec_helper'
+
+describe 'projects/commit/show.html.haml', :view do
+  let(:project) { create(:project, :repository) }
+
+  before do
+    assign(:project, project)
+    assign(:repository, project.repository)
+    assign(:commit, project.commit)
+    assign(:noteable, project.commit)
+    assign(:notes, [])
+    assign(:diffs, project.commit.diffs)
+
+    allow(view).to receive(:current_user).and_return(nil)
+    allow(view).to receive(:can?).and_return(false)
+    allow(view).to receive(:can_collaborate_with_project?).and_return(false)
+    allow(view).to receive(:current_ref).and_return(project.repository.root_ref)
+    allow(view).to receive(:diff_btn).and_return('')
+  end
+
+  context 'inline diff view' do
+    before do
+      allow(view).to receive(:diff_view).and_return(:inline)
+
+      render
+    end
+
+    it 'keeps container-limited' do
+      expect(rendered).not_to have_selector('.limit-container-width')
+    end
+  end
+
+  context 'parallel diff view' do
+    before do
+      allow(view).to receive(:diff_view).and_return(:parallel)
+
+      render
+    end
+
+    it 'spans full width' do
+      expect(rendered).to have_selector('.limit-container-width')
+    end
+  end
+end