Fix crash when using q=string as parameter

lib/ransack/helpers/form_helper.rb

@@ -180,7 +180,8 @@ def search_and_sort_params
           end
 
           def search_params
-            @params[@search.context.search_key].presence || {}
+            query_params = @params[@search.context.search_key]
+            query_params.is_a?(Hash) ? query_params : {}
           end
 
           def sort_params

spec/ransack/helpers/form_helper_spec.rb

@@ -140,6 +140,32 @@ module Helpers
         }
       end
 
+      describe '#sort_link works even if search params are a string' do
+        before { @controller.view_context.params[:q] = 'input error' }
+        specify {
+          expect { @controller.view_context
+            .sort_link(
+              Person.ransack({}),
+              :name,
+              controller: 'people'
+            )
+          }.not_to raise_error
+        }
+      end
+
+      describe '#sort_url works even if search params are a string' do
+        before { @controller.view_context.params[:q] = 'input error' }
+        specify {
+          expect { @controller.view_context
+            .sort_url(
+              Person.ransack({}),
+              :name,
+              controller: 'people'
+            )
+          }.not_to raise_error
+        }
+      end
+
       describe '#sort_link with search_key defined as a string' do
         subject { @controller.view_context
           .sort_link(