Fire after-fetch and after-git-fetch hooks even on failure

Wrap the fetch/checkout operations in begin/ensure so the after
hook fires even when the underlying fetch raises. This matches
the existing GEM_AFTER_INSTALL hook, which fires on both success
and failure paths (via internal error-to-state conversion in
ParallelInstaller#do_install).

Without this, plugins relying on before/after pairs for cleanup
or timing would see unbalanced hook invocations whenever a
network or checkout error occurs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hsbt

bundler/lib/bundler/source/git.rb

@@ -192,9 +192,12 @@ def specs(*)
 
         if requires_checkout? && !@copied
           Plugin.hook(Plugin::Events::GIT_BEFORE_FETCH, self)
-          fetch unless use_app_cache?
-          checkout
-          Plugin.hook(Plugin::Events::GIT_AFTER_FETCH, self)
+          begin
+            fetch unless use_app_cache?
+            checkout
+          ensure
+            Plugin.hook(Plugin::Events::GIT_AFTER_FETCH, self)
+          end
         end
 
         local_specs

bundler/lib/bundler/source/rubygems.rb

@@ -478,10 +478,13 @@ def download_gem(spec, download_cache_path, previous_spec = nil)
         gem_remote_fetcher = remote_fetchers.fetch(spec.remote).gem_remote_fetcher
 
         Plugin.hook(Plugin::Events::GEM_BEFORE_FETCH, spec)
-        Gem.time("Downloaded #{spec.name} in", 0, true) do
-          Bundler.rubygems.download_gem(spec, uri, download_cache_path, gem_remote_fetcher)
+        begin
+          Gem.time("Downloaded #{spec.name} in", 0, true) do
+            Bundler.rubygems.download_gem(spec, uri, download_cache_path, gem_remote_fetcher)
+          end
+        ensure
+          Plugin.hook(Plugin::Events::GEM_AFTER_FETCH, spec)
         end
-        Plugin.hook(Plugin::Events::GEM_AFTER_FETCH, spec)
       end
 
       # Returns the global cache path of the calling Rubygems::Source object.