Ensure commits limit is always positive

Changelog: fixed

app/controllers/projects/commits_controller.rb

@@ -63,7 +63,9 @@ class Projects::CommitsController < Projects::ApplicationController
 
   def set_commits
     render_404 unless @path.empty? || request.format == :atom || @repository.blob_at(@commit.id, @path) || @repository.tree(@commit.id, @path).entries.present?
-    @limit = (params[:limit] || 40).to_i
+
+    limit = params[:limit].to_i
+    @limit = limit > 0 ? limit : 40 # limit can only ever be a positive number
     @offset = (params[:offset] || 0).to_i
     search = params[:search]
     author = params[:author]

spec/controllers/projects/commits_controller_spec.rb

@@ -67,6 +67,22 @@ RSpec.describe Projects::CommitsController do
         end
       end
 
+      context "with an invalid limit" do
+        before do
+          get(:show,
+              params: {
+                namespace_id: project.namespace,
+                project_id: project,
+                id: id,
+                limit: "foo"
+            })
+        end
+
+        let(:id) { 'master/README.md' }
+
+        it { is_expected.to respond_with(:success) }
+      end
+
       context "when the ref name ends in .atom" do
         context "when the ref does not exist with the suffix" do
           before do