[rubygems/rubygems] Make plugin installation idempotent

The error had not be caught be specs because `bundle install` was
returning a zero exit code when plugin installation errors happened. So
I fixed that issue too.

https://github.com/rubygems/rubygems/commit/90cde87856

1 files changed, 8 insertions, 4 deletions

diff --git a/lib/bundler/plugin.rb b/lib/bundler/plugin.rb
index ab4b209f6e..158c69e1a1 100644
--- a/lib/bundler/plugin.rb
+++ b/lib/bundler/plugin.rb
@@ -13,6 +13,7 @@ module Bundler
     class MalformattedPlugin < PluginError; end
     class UndefinedCommandError < PluginError; end
     class UnknownSourceError < PluginError; end
+    class PluginInstallError < PluginError; end
 
     PLUGIN_FILE_NAME = "plugins.rb".freeze
 
@@ -38,12 +39,11 @@ module Bundler
       specs = Installer.new.install(names, options)
 
       save_plugins names, specs
-    rescue PluginError => e
+    rescue PluginError
       specs_to_delete = specs.select {|k, _v| names.include?(k) && !index.commands.values.include?(k) }
       specs_to_delete.each_value {|spec| Bundler.rm_rf(spec.full_gem_path) }
 
-      names_list = names.map {|name| "`#{name}`" }.join(", ")
-      Bundler.ui.error "Failed to install the following plugins: #{names_list}. The underlying error was: #{e.message}.\n #{e.backtrace.join("\n ")}"
+      raise
     end
 
     # Uninstalls plugins by the given names
@@ -245,6 +245,8 @@ module Bundler
     # @param [Array<String>] names of inferred source plugins that can be ignored
     def save_plugins(plugins, specs, optional_plugins = [])
       plugins.each do |name|
+        next if index.installed?(name)
+
         spec = specs[name]
 
         save_plugin(name, spec, optional_plugins.include?(name))
@@ -269,11 +271,13 @@ module Bundler
     # @param [Boolean] optional_plugin, removed if there is conflict with any
     #                     other plugin (used for default source plugins)
     #
-    # @raise [MalformattedPlugin] if validation or registration raises any error
+    # @raise [PluginInstallError] if validation or registration raises any error
     def save_plugin(name, spec, optional_plugin = false)
       validate_plugin! Pathname.new(spec.full_gem_path)
       installed = register_plugin(name, spec, optional_plugin)
       Bundler.ui.info "Installed plugin #{name}" if installed
+    rescue PluginError => e
+      raise PluginInstallError, "Failed to install plugin `#{spec.name}`, due to #{e.class} (#{e.message})"
     end
 
     # Runs the plugins.rb file in an isolated namespace, records the plugin