Fix parsing of negative options.

Library/Homebrew/cli/parser.rb

@@ -73,6 +73,12 @@ module Homebrew
         description = option_to_description(*names) if description.nil?
         process_option(*names, description)
         @parser.public_send(method, *names, *wrap_option_desc(description)) do |value|
+          value = if names.any? { |name| name.start_with?("--[no-]") }
+            value
+          else
+            true
+          end
+
           set_switch(*names, value: value, from: :args)
         end
 

Library/Homebrew/test/cli/parser_spec.rb

@@ -15,7 +15,7 @@ describe Homebrew::CLI::Parser do
       allow(Homebrew::EnvConfig).to receive(:pry?).and_return(true)
     end
 
-    context "when using negative options" do
+    context "when using binary options" do
       subject(:parser) {
         described_class.new do
           switch "--[no-]positive"
@@ -33,6 +33,30 @@ describe Homebrew::CLI::Parser do
       end
     end
 
+    context "when using negative options" do
+      subject(:parser) {
+        described_class.new do
+          switch "--no-positive"
+        end
+      }
+
+      it "does not set the positive name" do
+        args = parser.parse(["--no-positive"])
+        expect(args.positive?).to be nil
+      end
+
+      it "fails when using the positive name" do
+        expect {
+          parser.parse(["--positive"])
+        }.to raise_error(/invalid option/)
+      end
+
+      it "sets the negative name to true if the negative flag is passed" do
+        args = parser.parse(["--no-positive"])
+        expect(args.no_positive?).to be true
+      end
+    end
+
     context "when `ignore_invalid_options` is true" do
       it "passes through invalid options" do
         args = parser.parse(["-v", "named-arg", "--not-a-valid-option"], ignore_invalid_options: true)