1 files changed, 18 insertions, 10 deletions
diff --git a/lib/rubygems/request_set/lockfile/parser.rb b/lib/rubygems/request_set/lockfile/parser.rb
index 18aaadf3bb..ebea940188 100644
--- a/lib/rubygems/request_set/lockfile/parser.rb
+++ b/lib/rubygems/request_set/lockfile/parser.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true
 class Gem::RequestSet::Lockfile::Parser
   ###
   # Parses lockfiles
@@ -325,15 +325,24 @@ class Gem::RequestSet::Lockfile::Parser
     @tokens.peek
   end
 
-  def pinned_requirement name # :nodoc:
-    spec = @set.sets.select { |set|
-      Gem::Resolver::GitSet    === set or
-        Gem::Resolver::VendorSet === set
-    }.map { |set|
-      set.specs[name]
-    }.compact.first
+  if [].respond_to? :flat_map
+    def pinned_requirement name # :nodoc:
+      requirement = Gem::Dependency.new name
+      specification = @set.sets.flat_map { |set|
+        set.find_all(requirement)
+      }.compact.first
 
-    spec.version
+      specification && specification.version
+    end
+  else # FIXME: remove when 1.8 is dropped
+    def pinned_requirement name # :nodoc:
+      requirement = Gem::Dependency.new name
+      specification = @set.sets.map { |set|
+        set.find_all(requirement)
+      }.flatten(1).compact.first
+
+      specification && specification.version
+    end
   end
 
   ##
@@ -343,4 +352,3 @@ class Gem::RequestSet::Lockfile::Parser
     @tokens.unshift token
   end
 end
-