Ruby » Ruby master

mkmf.rb: fix merge_libs

• lib/mkmf.rb (MakeMakefile#merge_libs): insert following reversal
  ordered elements just after the duplicated element, not overwriting
  successive elements. [ruby-core:50314] [Bug #7467]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39128 b2dd03c8-39d4-4d8f-98ff-823fe69b080e