fallback to 0.0 in case of no gutter, fixes #1343

Prefer fetch for default value

Co-authored-by: André Jährling <85166619+andreavocado@users.noreply.github.com>

Author: afdev82

lib/prawn/grid.rb

@@ -145,12 +145,12 @@ def subdivide(total, num, gutter)
 
       def apply_gutter(options)
         if options.key?(:gutter)
-          @gutter = Float(options[:gutter])
+          @gutter = Float(options.fetch(:gutter, 0.0))
           @row_gutter = @gutter
           @column_gutter = @gutter
         else
-          @row_gutter = Float(options[:row_gutter])
-          @column_gutter = Float(options[:column_gutter])
+          @row_gutter = Float(options.fetch(:row_gutter, 0.0))
+          @column_gutter = Float(options.fetch(:column_gutter, 0.0))
           @gutter = 0
         end
       end

spec/prawn/document_grid_spec.rb

@@ -13,6 +13,13 @@
       expect(pdf.grid.gutter).to eq(0.1)
     end
 
+    it 'allows definition of a grid without gutter' do
+      pdf.define_grid(columns: 3, rows: 5)
+      expect(pdf.grid.columns).to eq(3)
+      expect(pdf.grid.rows).to eq(5)
+      expect(pdf.grid.gutter).to eq(0.0)
+    end
+
     it 'allows re-definition of a grid' do
       pdf.define_grid(columns: 5, rows: 8, gutter: 0.1)
       expect(pdf.grid.columns).to eq(5)