file.c: clear tmp buffer on failures

Reduces GC malloc pressure (MAXPATHLEN is 4096 on my system),
rb_find_file_safe hits this path at least twice every time
ruby starts.

* file.c (rb_find_file_ext_safe): clear tmp buffer on failure
  (rb_find_file_safe): ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47664 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 7 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index a8110e4d67..b5eb7e536b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Sep 21 12:19:29 2014  Eric Wong  <e@80x24.org>
+
+	* file.c (rb_find_file_ext_safe): clear tmp buffer on failure
+	  (rb_find_file_safe): ditto
+
 Sat Sep 20 04:42:18 2014  Masaki Matsushita <glass.saga@gmail.com>
 
 	* lib/csv.rb: avoid unnecessary object allocations.
diff --git a/file.c b/file.c
index 34b2693430..f6271a3607 100644
--- a/file.c
+++ b/file.c
@@ -5609,6 +5609,7 @@ rb_find_file_ext_safe(VALUE *filep, const char *const *ext, int safe_level)
 	}
 	rb_str_set_len(fname, fnlen);
     }
+    rb_str_resize(tmp, 0);
     RB_GC_GUARD(load_path);
     return 0;
 }
@@ -5661,6 +5662,7 @@ rb_find_file_safe(VALUE path, int safe_level)
 		if (rb_file_load_ok(f)) goto found;
 	    }
 	}
+	rb_str_resize(tmp, 0);
 	return 0;
     }
     else {