[bundler/bundler] Stop printing deprecation messages during specs

Previously under some circunstances (met during some specs), bundler
would print deprecations to a separate UI different from "bundler's UI".
This UI would not be captured by the specs, and thus would be printed to
screen during the specs.

This commit fixes that by making sure all deprecation messages always go
through bundler's UI.

220c54b7fa

lib/bundler/shared_helpers.rb

@@ -133,8 +133,9 @@ module Bundler
 
       return unless bundler_major_version >= major_version && prints_major_deprecations?
       @major_deprecation_ui ||= Bundler::UI::Shell.new("no-color" => true)
-      ui = Bundler.ui.is_a?(@major_deprecation_ui.class) ? Bundler.ui : @major_deprecation_ui
-      ui.warn("[DEPRECATED] #{message}")
+      with_major_deprecation_ui do |ui|
+        ui.warn("[DEPRECATED] #{message}")
+      end
     end
 
     def print_major_deprecations!
@@ -211,6 +212,21 @@ module Bundler
 
   private
 
+    def with_major_deprecation_ui(&block)
+      ui = Bundler.ui
+
+      if ui.is_a?(@major_deprecation_ui.class)
+        yield ui
+      else
+        begin
+          Bundler.ui = @major_deprecation_ui
+          yield Bundler.ui
+        ensure
+          Bundler.ui = ui
+        end
+      end
+    end
+
     def validate_bundle_path
       path_separator = Bundler.rubygems.path_separator
       return unless Bundler.bundle_path.to_s.split(path_separator).size > 1