Fix dependency equality

Library/Homebrew/dependencies.rb

@@ -10,7 +10,7 @@ class Dependencies
   end
 
   def <<(o)
-    @deps << o unless include?(o)
+    @deps << o
     self
   end
 

Library/Homebrew/dependency.rb

@@ -20,12 +20,12 @@ class Dependency
   end
 
   def ==(other)
-    instance_of?(other.class) && name == other.name
+    instance_of?(other.class) && name == other.name && tags == other.tags
   end
   alias_method :eql?, :==
 
   def hash
-    name.hash
+    name.hash ^ tags.hash
   end
 
   def to_formula
@@ -118,12 +118,11 @@ class Dependency
       throw(:action, :keep_but_prune_recursive_deps)
     end
 
-    def merge_repeats(deps)
-      grouped = deps.group_by(&:name)
-
-      deps.uniq.map do |dep|
-        tags = grouped.fetch(dep.name).map(&:tags).flatten.uniq
-        dep.class.new(dep.name, tags, dep.env_proc)
+    def merge_repeats(all)
+      all.group_by(&:name).map do |name, deps|
+        dep  = deps.first
+        tags = deps.map(&:tags).flatten.uniq
+        dep.class.new(name, tags, dep.env_proc)
       end
     end
   end

Library/Homebrew/test/test_dependencies.rb

@@ -12,13 +12,6 @@ class DependenciesTests < Homebrew::TestCase
     assert_same @deps, @deps << Dependency.new("foo")
   end
 
-  def test_no_duplicate_deps
-    @deps << Dependency.new("foo")
-    @deps << Dependency.new("foo", [:build])
-    @deps << Dependency.new("foo", [:build])
-    assert_equal 1, @deps.count
-  end
-
   def test_preserves_order
     hash = { 0 => "foo", 1 => "bar", 2 => "baz" }
     @deps << Dependency.new(hash[0])

Library/Homebrew/test/test_dependency.rb

@@ -47,5 +47,8 @@ class DependencyTests < Homebrew::TestCase
     assert_eql foo1, foo2
     refute_equal foo1, bar
     refute_eql foo1, bar
+    foo3 = Dependency.new("foo", [:build])
+    refute_equal foo1, foo3
+    refute_eql foo1, foo3
   end
 end

Library/Homebrew/test/test_dependency_collector.rb

@@ -37,13 +37,6 @@ class DependencyCollectorTests < Homebrew::TestCase
     assert_empty Dependency.new('foo').tags
   end
 
-  def test_no_duplicate_dependencies
-    @d.add 'foo'
-    @d.add 'foo' => :build
-    assert_equal 1, @d.deps.count
-    assert_empty find_dependency("foo").tags
-  end
-
   def test_requirement_creation
     @d.add :x11
     assert_instance_of X11Dependency, find_requirement(X11Dependency)

Library/Homebrew/test/test_dependency_expansion.rb

@@ -100,16 +100,15 @@ class DependencyExpansionTests < Homebrew::TestCase
   end
 
   def test_keep_dep_but_prune_recursive_deps
-    f = stub(:name => "f", :deps => [
-      build_dep(:foo, [:build], [@bar]),
-      build_dep(:baz, [:build]),
-    ])
+    foo = build_dep(:foo, [:build], @bar)
+    baz = build_dep(:baz, [:build])
+    f = stub(:name => "f", :deps => [foo, baz])
 
     deps = Dependency.expand(f) do |dependent, dep|
       Dependency.keep_but_prune_recursive_deps if dep.build?
     end
 
-    assert_equal [@foo, @baz], deps
+    assert_equal [foo, baz], deps
   end
 
   def test_deps_with_collection_argument