Use default_release option when name is not given (#9158)

Author: christopher-dG

lib/mix/lib/mix/release.ex

@@ -178,10 +178,16 @@ defmodule Mix.Release do
         {name, opts}
 
       [_ | _] ->
-        Mix.raise(
-          "\"mix release\" was invoked without a name but there are multiple releases. " <>
-            "Please call \"mix release NAME\" or set :default_release in your project configuration"
-        )
+        case Keyword.get(config, :default_release) do
+          nil ->
+            Mix.raise(
+              "\"mix release\" was invoked without a name but there are multiple releases. " <>
+                "Please call \"mix release NAME\" or set :default_release in your project configuration"
+            )
+
+          name ->
+            lookup_release(name, config)
+        end
     end
   end
 

lib/mix/test/mix/release_test.exs

@@ -95,7 +95,7 @@ defmodule Mix.ReleaseTest do
     test "uses chosen release via the default_release" do
       release =
         from_config!(
-          :bar,
+          nil,
           config(
             default_release: :bar,
             releases: [foo: [version: "0.2.0"], bar: [version: "0.3.0"]]