Allow installing / updating when everything necessary is available locally

3 files changed, 22 insertions, 7 deletions

diff --git a/lib/bundler/fetcher/compact_index.rb b/lib/bundler/fetcher/compact_index.rb
index b51ba150a9..fb77451822 100644
--- a/lib/bundler/fetcher/compact_index.rb
+++ b/lib/bundler/fetcher/compact_index.rb
@@ -78,11 +78,7 @@ module Bundler
     private
 
       def compact_index_client
-        @compact_index_client ||= begin
-          compact_fetcher = lambda do |path, headers|
-            downloader.fetch(fetch_uri + path, headers)
-          end
-
+        @compact_index_client ||=
           SharedHelpers.filesystem_access(cache_path) do
             CompactIndexClient.new(cache_path, compact_fetcher)
           end.tap do |client|
@@ -93,7 +89,6 @@ module Bundler
               inputs.map { worker.deq }
             end
           end
-        end
       end
 
       def bundle_worker(func = nil)
@@ -109,6 +104,18 @@ module Bundler
       def cache_path
         Bundler.user_cache.join("compact_index", remote.cache_slug)
       end
+
+      def compact_fetcher
+        lambda do |path, headers|
+          begin
+            downloader.fetch(fetch_uri + path, headers)
+          rescue NetworkDownError => e
+            raise unless Bundler.settings[:allow_offline_install] && headers["If-None-Match"]
+            Bundler.ui.warn "Using the cached data for the new index because of a network error: #{e}"
+            Net::HTTPNotModified.new(nil, nil, nil)
+          end
+        end
+      end
     end
   end
 end
diff --git a/lib/bundler/settings.rb b/lib/bundler/settings.rb
index 0c846d195c..e5c2581067 100644
--- a/lib/bundler/settings.rb
+++ b/lib/bundler/settings.rb
@@ -4,6 +4,7 @@ require "uri"
 module Bundler
   class Settings
     BOOL_KEYS = %w(
+      allow_offline_install
       cache_all
       disable_local_branch_check
       disable_shared_gems
diff --git a/lib/bundler/source/git.rb b/lib/bundler/source/git.rb
index 5344ab694f..60fb555f0a 100644
--- a/lib/bundler/source/git.rb
+++ b/lib/bundler/source/git.rb
@@ -152,7 +152,7 @@ module Bundler
         set_local!(app_cache_path) if has_app_cache? && !local?
 
         if requires_checkout? && !@copied
-          git_proxy.checkout
+          fetch
           git_proxy.copy_to(install_path, submodules)
           serialize_gemspecs_in(install_path)
           @copied = true
@@ -288,6 +288,13 @@ module Bundler
       def git_proxy
         @git_proxy ||= GitProxy.new(cache_path, uri, ref, cached_revision, self)
       end
+
+      def fetch
+        git_proxy.checkout
+      rescue GitError
+        raise unless Bundler.settings[:allow_offline_install]
+        Bundler.ui.warn "Using cached git data because of network errors"
+      end
     end
   end
 end