Merge branch 'track_bundler_version_in_lock'

lib/bundler/definition.rb

@@ -256,9 +256,39 @@ def lock(file)
         "#{File.expand_path(file)}"
     end
 
+    # Returns the version of Bundler that is creating or has created
+    # Gemfile.lock. Used in #to_lock.
+    def lock_version
+      lockfile = @lockfile_contents
+      lock_ver = ""
+      curr_ver = ""
+
+      if !lockfile.empty? and lockfile.match(/^  \[(.*)\]$/)
+        lock_ver = $1
+        curr_ver = Bundler::VERSION
+      end
+
+      if !lock_ver.empty? and !curr_ver.empty?
+        if Gem::Version.new(curr_ver) >= Gem::Version.new(lock_ver)
+          ver = curr_ver
+        else
+          ver = lock_ver
+        end
+      else
+        ver = Bundler::VERSION
+      end
+
+      ver
+    end
+
     def to_lock
       out = ""
 
+      # Record the version of Bundler that was used to create the lockfile
+      out << "LOCKED WITH\n"
+      out << "  [#{lock_version}]\n"
+      out << "\n"
+
       sources.lock_sources.each do |source|
         # Add the source header
         out << source.to_lock

lib/bundler/lockfile_parser.rb

@@ -14,6 +14,7 @@ module Bundler
   class LockfileParser
     attr_reader :sources, :dependencies, :specs, :platforms
 
+    LOCKED       = "LOCKED WITH"
     DEPENDENCIES = "DEPENDENCIES"
     PLATFORMS    = "PLATFORMS"
     GIT          = "GIT"
@@ -31,6 +32,22 @@ def initialize(lockfile)
 
       @rubygems_aggregate = Source::Rubygems.new
 
+
+      # If the lockfile's recorded version is older than the current version
+      # of Bundler, we warn the user to update Bundler.
+      if lockfile.match(/^  \[(.*)\]$/)
+        lock_ver = $1
+        curr_ver = Bundler::VERSION
+        prerelease_text = lock_ver.match(/pre/) ? " --pre" : ""
+
+        if Gem::Version.new(curr_ver) < Gem::Version.new(lock_ver)
+          Bundler.ui.warn "Warning: the running version of Bundler is older " \
+               "than the version that created the lockfile. We suggest you " \
+               "upgrade to the latest version of Bundler by running `gem " \
+               "install bundler#{prerelease_text}`.\n"
+        end
+      end
+
       if lockfile.match(/<<<<<<<|=======|>>>>>>>|\|\|\|\|\|\|\|/)
         raise LockfileError, "Your Gemfile.lock contains merge conflicts.\n" \
           "Run `git checkout HEAD -- Gemfile.lock` first to get a clean lock."