[Definition] Dont updated bundled with when 100% unnecessaryseg-bundled-with

2 files changed, 52 insertions, 11 deletions

diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index 81401ff81a..be3c2eca43 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -248,23 +248,24 @@ module Bundler
       # i.e., Windows with `git config core.autocrlf=true`
       contents.gsub!(/\n/, "\r\n") if @lockfile_contents.match("\r\n")
 
-      return if lockfiles_equal?(@lockfile_contents, contents, preserve_bundled_with)
-
-      if Bundler.settings[:frozen]
-        Bundler.ui.error "Cannot write a changed lockfile while frozen."
-        return
-      end
-
       if @locked_bundler_version
         locked_major = @locked_bundler_version.segments.first
         current_major = Gem::Version.create(Bundler::VERSION).segments.first
 
-        if locked_major < current_major
-          Bundler.ui.warn "Warning: the lockfile is being updated to Bundler #{Bundler::VERSION.split('.').first}, " \
+        if updating_major = locked_major < current_major
+          Bundler.ui.warn "Warning: the lockfile is being updated to Bundler #{current_major}, " \
                           "after which you will be unable to return to Bundler #{@locked_bundler_version.segments.first}."
         end
       end
 
+      preserve_bundled_with ||= !updating_major && (Bundler.settings[:frozen] || !@unlocking)
+      return if lockfiles_equal?(@lockfile_contents, contents, preserve_bundled_with)
+
+      if Bundler.settings[:frozen]
+        Bundler.ui.error "Cannot write a changed lockfile while frozen."
+        return
+      end
+
       File.open(file, 'wb'){|f| f.puts(contents) }
     rescue Errno::EACCES
       raise Bundler::InstallError,
diff --git a/spec/lock/lockfile_spec.rb b/spec/lock/lockfile_spec.rb
index 657f91a2c6..9f13a016d7 100644
--- a/spec/lock/lockfile_spec.rb
+++ b/spec/lock/lockfile_spec.rb
@@ -74,8 +74,7 @@ describe "the lockfile format" do
     G
   end
 
-  it "updates the lockfile's bundler version if not present" do
-
+  it "does not update the lockfile's bundler version if nothing changed during bundle install" do
     lockfile <<-L
       GEM
         remote: file:#{gem_repo1}/
@@ -87,6 +86,9 @@ describe "the lockfile format" do
 
       DEPENDENCIES
         rack
+
+      BUNDLED WITH
+         1.10.0
     L
 
     install_gemfile <<-G
@@ -108,6 +110,44 @@ describe "the lockfile format" do
         rack
 
       BUNDLED WITH
+         1.10.0
+    G
+  end
+
+  it "updates the lockfile's bundler version if not present" do
+
+    lockfile <<-L
+      GEM
+        remote: file:#{gem_repo1}/
+        specs:
+          rack (1.0.0)
+
+      PLATFORMS
+        #{generic(Gem::Platform.local)}
+
+      DEPENDENCIES
+        rack
+    L
+
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+
+      gem "rack", "> 0"
+    G
+
+    lockfile_should_be <<-G
+      GEM
+        remote: file:#{gem_repo1}/
+        specs:
+          rack (1.0.0)
+
+      PLATFORMS
+        #{generic(Gem::Platform.local)}
+
+      DEPENDENCIES
+        rack (> 0)
+
+      BUNDLED WITH
          #{Bundler::VERSION}
     G
   end