[PATCH] extconf: fix rb_hash_aset deduplication test

[PATCH] extconf: fix rb_hash_aset deduplication test

[Eric Wong]

We must rely on a random string which is already outside
of the Ruby fstring table.
---
 ext/kcar/extconf.rb | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/ext/kcar/extconf.rb b/ext/kcar/extconf.rb
index ba69c3c..1608f70 100644
--- a/ext/kcar/extconf.rb
+++ b/ext/kcar/extconf.rb
@@ -24,8 +24,11 @@ end
 
 message('checking if Hash#[]= (rb_hash_aset) dedupes... ')
 h = {}
-h[%w(m k m f).join('')] = :foo
-if 'mkmf'.freeze.equal?(h.keys[0])
+x = {}
+r = rand.to_s
+h[%W(#{r}).join('')] = :foo
+x[%W(#{r}).join('')] = :foo
+if x.keys[0].equal?(h.keys[0])
   $CPPFLAGS += ' -DHASH_ASET_DEDUPE=1 '
   message("yes\n")
 else
-- 
EW