1 files changed, 7 insertions, 0 deletions
diff --git a/lib/rubygems/installer.rb b/lib/rubygems/installer.rb
index 967543c2d1..6fd3399dd4 100644
--- a/lib/rubygems/installer.rb
+++ b/lib/rubygems/installer.rb
@@ -697,6 +697,11 @@ class Gem::Installer
       unpack or File.writable?(gem_home)
   end
 
+  def verify_spec_name
+    return if spec.name =~ Gem::Specification::VALID_NAME_PATTERN
+    raise Gem::InstallError, "#{spec} has an invalid name"
+  end
+
   ##
   # Return the text for an application file.
 
@@ -823,6 +828,8 @@ TEXT
 
     ensure_loadable_spec
 
+    verify_spec_name
+
     if options[:install_as_default]
       Gem.ensure_default_gem_subdirectories gem_home
     else