Avoid to crash when there is not a software section

AutoinstFunction#base_product_name was crashing when given profile had
not a valid `software` section, which could happen due to several
reasons. For example, a not valid XML syntax or simply a user oversight.

It was failing with

> undefined method 'fetch' for nil:NilClass"

Related to bsc#1125959

src/modules/AutoinstFunctions.rb

@@ -136,7 +136,7 @@ def identify_product
     # @return [Y2Packager::Product] a product if exactly one product matches
     # the criteria, nil otherwise
     def identify_product_by_patterns(profile)
-      software = profile.fetch("software", {})
+      software = profile["software"] || {}
 
       identify_product do |product|
         software.fetch("patterns", []).any? { |p| p =~ /#{product.name.downcase}-.*/ }
@@ -151,7 +151,7 @@ def identify_product_by_patterns(profile)
     # @return [Y2Packager::Product] a product if exactly one product matches
     # the criteria, nil otherwise
     def identify_product_by_packages(profile)
-      software = profile.fetch("software", {})
+      software = profile["software"] || {}
 
       identify_product do |product|
         software.fetch("packages", []).any? { |p| p =~ /#{product.name.downcase}-release/ }
@@ -180,8 +180,10 @@ def identify_product_by_selection(profile)
     # @param profile [Hash] AutoYaST profile
     # @return [String] product name
     def base_product_name(profile)
-      software = profile.fetch("software", {})
-      software.fetch("products", []).first
+      software = profile["software"] || {}
+      products = software["products"] || []
+
+      products.first
     end
   end
 

test/AutoinstFunctions_test.rb

@@ -177,4 +177,12 @@ def base_product(name)
       expect(subject.selected_product.name).to eql "SLED"
     end
   end
+
+  it "does not crash when there is not a software section" do
+      allow(Yast::Profile)
+        .to receive(:current)
+        .and_return("software" => nil)
+
+      expect(subject.selected_product).to be_nil
+  end
 end