Fix #6 Pre-1.0 upgrades should not be safe

rockspecs/semver-1.2.1-1.rockspec

@@ -0,0 +1,25 @@
+package = "semver"
+version = "1.2.1-1"
+source = {
+   url = "git://github.com/kikito/semver.lua.git",
+}
+description = {
+   summary = "An implementation of semantic versioning (semver.org 2.0.0) in Lua",
+   detailed = [[
+      See details in http://semver.org
+   ]],
+   license = "MIT",
+   homepage = "https://github.com/kikito/semver.lua"
+}
+dependencies = {
+   "lua >= 5.1"
+}
+
+build = {
+  type = "none",
+  install = {
+    lua = {
+      "semver.lua"
+    },
+  }
+}

semver.lua

@@ -1,5 +1,5 @@
 local semver = {
-  _VERSION     = '1.2.0',
+  _VERSION     = '1.2.1',
   _DESCRIPTION = 'semver for Lua',
   _URL         = 'https://github.com/kikito/semver.lua',
   _LICENSE     = [[
@@ -173,6 +173,9 @@ end
 -- if a and b are versions, a ^ b means "b is backwards-compatible with a"
 -- in other words, "it's safe to upgrade from a to b"
 function mt:__pow(other)
+  if self.major == 0 then
+    return self == other
+  end
   return self.major == other.major and
          self.minor <= other.minor
 end

spec/semver_spec.lua

@@ -254,6 +254,8 @@ describe('semver', function()
   describe("^", function()
     it("true for self", function()
       assert.is_true(v(1,2,3) ^ v(1,2,3))
+      assert.is_true(v(0,1,0) ^ v(0,1,0))
+      assert.is_true(v("0.1.1+build0") ^ v(0,1,1))
     end)
     it("different major versions mean it's always unsafe", function()
       assert.is_false(v(2,0,0) ^ v(3,0,0))
@@ -273,6 +275,15 @@ describe('semver', function()
     it("is unsafe to downgrade to an earlier minor version", function()
       assert.is_false(v(1,5,0) ^ v(1,2,0))
     end)
+
+    it("is unsafe to upgrade any pre-1.0 versions", function()
+      assert.is_false(v("0.0.1-alpha") ^ v(0,0,1))
+      assert.is_false(v("0.0.1") ^ v(0,0,2))
+      assert.is_false(v("0.0.1+build0") ^ v(0,0,2))
+      assert.is_false(v(0,0,1) ^ v(0,1,0))
+      assert.is_false(v(0,0,1) ^ v(1,0,0))
+      assert.is_false(v(0,0,1) ^ v("1.0.0-alpha"))
+    end)
   end)
 
   describe("_VERSION", function()