Encode formula revision in installation prefix

In order to allow kegs built with the same version but differing formula
revisions to coexist, we must encode the revision as part of the keg's
name. This is necessary to actually perform an upgrade, as we cannot
upgrade a keg in-place, and temporarily moving it pending the result of
the upgrade is error-prone and potentially slow.

To accomplish this, we introduce a new Formula#pkg_version method that
concatenates the active_spec version with the formula revision. An
exception is made for a formula that has no revision: the tag is
omitted. This preserves compatibility with existing installations.

1 files changed, 36 insertions, 0 deletions

diff --git a/Library/Homebrew/test/test_pkg_version.rb b/Library/Homebrew/test/test_pkg_version.rb
new file mode 100644
index 000000000..d78007dcf
--- /dev/null
+++ b/Library/Homebrew/test/test_pkg_version.rb
@@ -0,0 +1,36 @@
+require 'testing_env'
+require 'pkg_version'
+
+class PkgVersionTests < Test::Unit::TestCase
+  def v(version)
+    PkgVersion.parse(version)
+  end
+
+  def test_parse
+    assert_equal PkgVersion.new("1.0", 1), PkgVersion.parse("1.0_1")
+    assert_equal PkgVersion.new("1.0", 1), PkgVersion.parse("1.0_1")
+    assert_equal PkgVersion.new("1.0", 0), PkgVersion.parse("1.0")
+    assert_equal PkgVersion.new("1.0", 0), PkgVersion.parse("1.0_0")
+    assert_equal PkgVersion.new("2.1.4", 0), PkgVersion.parse("2.1.4_0")
+    assert_equal PkgVersion.new("2.1.4_1", 0), PkgVersion.parse("2.1.4_1_0")
+    assert_equal PkgVersion.new("1.0.1e", 1), PkgVersion.parse("1.0.1e_1")
+  end
+
+  def test_comparison
+    assert_operator v("1.0_0"), :==, v("1.0")
+    assert_operator v("1.0_1"), :==, v("1.0_1")
+    assert_operator v("1.1"), :>, v("1.0_1")
+    assert_operator v("1.0_0"), :==, v("1.0")
+    assert_operator v("1.0_1"), :<, v("2.0_1")
+    assert_operator v("HEAD"), :>, v("1.0")
+    assert_operator v("1.0"), :<, v("HEAD")
+  end
+
+  def test_to_s
+    assert_equal "1.0", PkgVersion.new("1.0", 0).to_s
+    assert_equal "1.0_1", PkgVersion.new("1.0", 1).to_s
+    assert_equal "1.0", PkgVersion.new("1.0", 0).to_s
+    assert_equal "1.0", PkgVersion.new("1.0", 0).to_s
+    assert_equal "HEAD", PkgVersion.new("HEAD", 1).to_s
+  end
+end