Set `RAILS_ENV` before load application file

Since #29725, load application file when `dbconsole` command is executed.
However, if do not set `RAILS_ENV` before reading the application file,
can not connect to the env specified in option, so added the setting
of `RAILS_ENV`.

railties/lib/rails/commands/dbconsole/dbconsole_command.rb

@@ -11,7 +11,7 @@ module Rails
     end
 
     def start
-      ENV["RAILS_ENV"] = @options[:environment] || environment
+      ENV["RAILS_ENV"] ||= @options[:environment] || environment
 
       case config["adapter"]
       when /^(jdbc)?mysql/
@@ -157,6 +157,9 @@ module Rails
       def perform
         extract_environment_option_from_argument
 
+        # RAILS_ENV needs to be set before config/application is required.
+        ENV["RAILS_ENV"] = options[:environment]
+
         require_application_and_environment!
         Rails::DBConsole.start(options)
       end

railties/test/application/dbconsole_test.rb

@@ -9,6 +9,8 @@ module ApplicationTests
     include ActiveSupport::Testing::Isolation
 
     def setup
+      skip "PTY unavailable" unless available_pty?
+
       build_app
     end
 
@@ -17,7 +19,6 @@ module ApplicationTests
     end
 
     def test_use_value_defined_in_environment_file_in_database_yml
-      skip "PTY unavailable" unless available_pty?
       Dir.chdir(app_path) do
         app_file "config/database.yml", <<-YAML
           development:
@@ -41,9 +42,37 @@ module ApplicationTests
       master.puts ".exit"
     end
 
+    def test_respect_environment_option
+      Dir.chdir(app_path) do
+        app_file "config/database.yml", <<-YAML
+          default: &default
+            adapter: sqlite3
+            pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
+            timeout: 5000
+
+          development:
+            <<: *default
+            database: db/development.sqlite3
+
+          production:
+            <<: *default
+            database: db/production.sqlite3
+        YAML
+      end
+
+      master, slave = PTY.open
+      spawn_dbconsole(slave, "-e production")
+      assert_output("sqlite>", master)
+
+      master.puts ".databases"
+      assert_output("production.sqlite3", master)
+    ensure
+      master.puts ".exit"
+    end
+
     private
-      def spawn_dbconsole(fd)
-        Process.spawn("#{app_path}/bin/rails dbconsole", in: fd, out: fd, err: fd)
+      def spawn_dbconsole(fd, options = nil)
+        Process.spawn("#{app_path}/bin/rails dbconsole #{options}", in: fd, out: fd, err: fd)
       end
 
       def assert_output(expected, io, timeout = 5)