Mark transitive-only overrides as changed against the lockfile

converge_dependencies only iterates @Dependencies (Gemfile-declared
direct deps), so an override that targets a gem present only as a
transitive dependency never registered as a change. With an existing
lockfile, @dependency_changes stayed false, the resolver was skipped,
and the override was a silent no-op. After the direct-dep loop,
inspect @OVERRIDES for any String target that is locked but not a
direct dep and force it onto @gems_to_unlock / @changed_dependencies
so resolution runs and the Resolver-side override hook applies.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hsbt

bundler/lib/bundler/definition.rb

@@ -1054,9 +1054,25 @@ def converge_dependencies
         @changed_dependencies << name if dep_changed
       end
 
+      converge_overrides_outside_dependencies
+
       @changed_dependencies.any?
     end
 
+    def converge_overrides_outside_dependencies
+      @overrides.each do |override|
+        next unless override.target.is_a?(String)
+
+        name = override.target
+        next if @changed_dependencies.include?(name)
+        next if @dependencies.any? {|d| d.name == name }
+        next if @originally_locked_specs[name].empty?
+
+        @gems_to_unlock << name
+        @changed_dependencies << name
+      end
+    end
+
     # Remove elements from the locked specs that are expired. This will most
     # commonly happen if the Gemfile has changed since the lockfile was last
     # generated

spec/install/gemfile/override_spec.rb

@@ -109,5 +109,24 @@
 
       expect(the_bundle).to include_gems "myrack 1.0.0", "myrack_middleware 1.0"
     end
+
+    it "applies a transitive-only override against an existing lockfile" do
+      install_gemfile <<-G
+        source "https://gem.repo1"
+        gem "myrack_middleware"
+      G
+
+      expect(the_bundle).to include_gems "myrack 0.9.1", "myrack_middleware 1.0"
+
+      gemfile <<-G
+        source "https://gem.repo1"
+        override "myrack", version: "= 1.0.0"
+        gem "myrack_middleware"
+      G
+
+      bundle :install
+
+      expect(the_bundle).to include_gems "myrack 1.0.0", "myrack_middleware 1.0"
+    end
   end
 end