Use BSD tar's libarchive LZMA support if available

Avoid using an unnecessary `xz` dependency when it's not needed.

2 files changed, 19 insertions, 6 deletions

diff --git a/Library/Homebrew/test/test_dependency_collector.rb b/Library/Homebrew/test/test_dependency_collector.rb
index 4e87c8515..1c7f70118 100644
--- a/Library/Homebrew/test/test_dependency_collector.rb
+++ b/Library/Homebrew/test/test_dependency_collector.rb
@@ -114,12 +114,6 @@ class DependencyCollectorTests < Homebrew::TestCase
     assert_nil @d.add(resource)
   end
 
-  def test_resource_dep_xz_url
-    resource = Resource.new
-    resource.url("http://example.com/foo.tar.xz")
-    assert_equal Dependency.new("xz", [:build]), @d.add(resource)
-  end
-
   def test_resource_dep_lz_url
     resource = Resource.new
     resource.url("http://example.com/foo.lz")
diff --git a/Library/Homebrew/test/test_os_mac_dependency_collector.rb b/Library/Homebrew/test/test_os_mac_dependency_collector.rb
index 05b466c94..d3a45b1fb 100644
--- a/Library/Homebrew/test/test_os_mac_dependency_collector.rb
+++ b/Library/Homebrew/test/test_os_mac_dependency_collector.rb
@@ -14,6 +14,11 @@ class OSMacDependencyCollectorTests < Homebrew::TestCase
     DependencyCollector.clear_cache
   end
 
+  def test_tar_needs_xz_dependency
+    MacOS.stubs(:version).returns(MacOS::Version.new("10.7"))
+    refute DependencyCollector.tar_needs_xz_dependency?
+  end
+
   def test_ld64_dep_pre_leopard
     MacOS.stubs(:version).returns(MacOS::Version.new("10.4"))
     assert_equal LD64Dependency.new, @d.build(:ld64)
@@ -35,4 +40,18 @@ class OSMacDependencyCollectorTests < Homebrew::TestCase
     @d.add ant: :build
     assert_nil find_dependency("ant")
   end
+
+  def test_resource_dep_xz_url_pre_lion
+    MacOS.stubs(:version).returns(MacOS::Version.new("10.6"))
+    resource = Resource.new
+    resource.url("http://example.com/foo.tar.xz")
+    assert_equal Dependency.new("xz", [:build]), @d.add(resource)
+  end
+
+  def test_resource_dep_xz_lion_or_newer
+    MacOS.stubs(:version).returns(MacOS::Version.new("10.7"))
+    resource = Resource.new
+    resource.url("http://example.com/foo.tar.xz")
+    assert_nil @d.add(resource)
+  end
 end