Fix selenium issue with fieldset nested in disabled fieldset not being disabled

lib/capybara/selector.rb

@@ -74,6 +74,8 @@ Capybara.add_selector(:fieldset) do
     xpath = xpath[XPath.child(:legend)[XPath.string.n.is(legend)]] if legend
     xpath
   end
+
+  node_filter(:disabled, :boolean) { |node, value| !(value ^ node.disabled?) }
 end
 
 Capybara.add_selector(:link) do

lib/capybara/selenium/node.rb

@@ -142,8 +142,7 @@ class Capybara::Selenium::Node < Capybara::Driver::Node
   def disabled?
     return true unless native.enabled?
     # WebDriver only defines `disabled?` for form controls but fieldset makes sense too
-    return boolean_attr(self[:disabled]) if tag_name == 'fieldset'
-    false
+    tag_name == 'fieldset' && find_xpath("ancestor-or-self::fieldset[@disabled]").any?
   end
 
   def content_editable?

lib/capybara/selenium/nodes/marionette_node.rb

@@ -13,8 +13,10 @@ class Capybara::Selenium::MarionetteNode < Capybara::Selenium::Node
   end
 
   def disabled?
-    return true if super
+    # Not sure exactly what version of FF fixed the below issue, but it is definitely fixed in 61+
+    return super unless driver.browser.capabilities[:browser_version].to_f < 61.0
 
+    return true if super
     # workaround for selenium-webdriver/geckodriver reporting elements as enabled when they are nested in disabling elements
     if %w[option optgroup].include? tag_name
       find_xpath("parent::*[self::optgroup or self::select]")[0].disabled?

lib/capybara/spec/session/node_spec.rb

@@ -208,6 +208,12 @@ Capybara::SpecHelper.spec "node" do
       expect(@session.find('//select[@id="form_disabled_select2"]/option').disabled?).to be true
       expect(@session.find('//select[@id="form_title"]/option[1]').disabled?).to be false
     end
+
+    it "should be disabled for all elements that are CSS :disabled" do
+      @session.visit('/form')
+      # sanity check
+      expect(@session.all(:css, ':disabled')).to all(be_disabled)
+    end
   end
 
   describe "#visible?" do

lib/capybara/spec/views/form.erb

@@ -370,7 +370,6 @@ New line after and before textarea tag
     </label>
   </p>
 
-
   <p>
     <label for="form_disabled_file">
       Disabled File
@@ -378,38 +377,35 @@ New line after and before textarea tag
     </label>
   </p>
 
-  <p>
+  <fieldset>
+    <input name="form[enabled_fieldset_child]" id="form_enabled_fieldset_child"/>
+  </fieldset>
+
+  <fieldset disabled="disabled" id="form_disabled_fieldset">
+    <legend>Disabled Child</legend>
+    <input name="form[disabled_fieldset_child]" id="form_disabled_fieldset_child"/>
+    <select>
+      <option>Disabled Child Option</option>
+    </select>
+  </fieldset>
+
+  <fieldset disabled="disabled">
+    <legend>
+      Nested Disabled
+      <input type="checkbox" name="form[disabled_fieldeset_legend_child]" id="form_disabled_fieldset_legend_child"/>
+    </legend>
+    <legend>
+      Another Legend
+      <input type="checkbox" name="form[disabled_fieldeset_second_legend_child]" id="form_disabled_fieldset_second_legend_child"/>
+    </legend>
     <fieldset>
-        <input name="form[enabled_fieldset_child]" id="form_enabled_fieldset_child"/>
-    </fieldset>
-  </p>
-
-
-  <p>
-    <fieldset disabled="disabled" id="form_disabled_fieldset">
-      <legend>Disabled Child</legend>
-      <input name="form[disabled_fieldset_child]" id="form_disabled_fieldset_child"/>
-      <select>
-        <option>Disabled Child Option</option>
-      </select>
-    </fieldset>
-
-    <fieldset disabled="disabled">
       <legend>
-        Nested Disabled
-        <input type="checkbox" name="form[disabled_fieldeset_legend_child]" id="form_disabled_fieldset_legend_child"/>
+        Disabled?
+        <input id="form_disabled_fieldset_descendant_legend_child">
       </legend>
-      <legend>
-        Another Legend
-        <input type="checkbox" name="form[disabled_fieldeset_second_legend_child]" id="form_disabled_fieldset_second_legend_child"/>
-      </legend>
-      <p>
-        <fieldset>
-          <input name="form[disabled_fieldset_descendant]" id="form_disabled_fieldset_descendant"/>
-        </fieldset>
-      </p>
+      <input name="form[disabled_fieldset_descendant]" id="form_disabled_fieldset_descendant"/>
     </fieldset>
-  </p>
+  </fieldset>
 
   <p>
     <select>
@@ -461,7 +457,7 @@ New line after and before textarea tag
 </form>
 
 <form id="form2" action="/form" method="post">
-  <input type="text" name="form[which_form]" value="form2" id="form_which_form"/>
+  <input type="text" name="form[which_form]" value="form2" id="form_which_form2"/>
   <input type="submit" name="form[unused]" value="unused"/>
   <button type="submit" name="form[other_form_button]" value="other_form_button" form="form1">Form1</button>
 </form>