merge revision(s) r46408,r46410,r46413,r46414,r46424,r46436,r46437: [Backport #9934]

	string.c: shrink too big buffer

	* string.c (rb_str_resize): shrink the buffer even if new length
  is same but it is enough smaller than the capacity.
	* file.c (expand_path): shrink expanded path which no longer needs
	  rooms to append.  [ruby-core:63114] [Bug #9934]

	* string.c (rb_str_resize): should consider the capacity instead
	  of the old length, as pointed out by nagachika.

	* string.c (rb_str_resize): update capa only when buffer get
	  reallocated.
	  http://d.hatena.ne.jp/nagachika/20140613/ruby_trunk_changes_46413_46420#r46413


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@47215 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 14 insertions, 3 deletions

diff --git a/file.c b/file.c
index 77facacfcf..e9e2dd1340 100644
--- a/file.c
+++ b/file.c
@@ -3397,6 +3397,16 @@ rb_file_expand_path_internal(VALUE fname, VALUE dname, int abs_mode, int long_na
 
 #define EXPAND_PATH_BUFFER() rb_usascii_str_new(0, MAXPATHLEN + 2)
 
+static VALUE
+str_shrink(VALUE str)
+{
+    rb_str_resize(str, RSTRING_LEN(str));
+    return str;
+}
+
+#define expand_path(fname, dname, abs_mode, long_name, result) \
+    str_shrink(rb_file_expand_path_internal(fname, dname, abs_mode, long_name, result))
+
 #define check_expand_path_args(fname, dname) \
     (((fname) = rb_get_path(fname)), \
      (void)(NIL_P(dname) ? (dname) : ((dname) = rb_get_path(dname))))
@@ -3411,13 +3421,13 @@ VALUE
 rb_file_expand_path(VALUE fname, VALUE dname)
 {
     check_expand_path_args(fname, dname);
-    return rb_file_expand_path_internal(fname, dname, 0, 1, EXPAND_PATH_BUFFER());
+    return expand_path(fname, dname, 0, 1, EXPAND_PATH_BUFFER());
 }
 
 VALUE
 rb_file_expand_path_fast(VALUE fname, VALUE dname)
 {
-    return rb_file_expand_path_internal(fname, dname, 0, 0, EXPAND_PATH_BUFFER());
+    return expand_path(fname, dname, 0, 0, EXPAND_PATH_BUFFER());
 }
 
 /*
@@ -3465,7 +3475,7 @@ VALUE
 rb_file_absolute_path(VALUE fname, VALUE dname)
 {
     check_expand_path_args(fname, dname);
-    return rb_file_expand_path_internal(fname, dname, 1, 1, EXPAND_PATH_BUFFER());
+    return expand_path(fname, dname, 1, 1, EXPAND_PATH_BUFFER());
 }
 
 /*
@@ -5408,6 +5418,7 @@ is_explicit_relative(const char *path)
 static VALUE
 copy_path_class(VALUE path, VALUE orig)
 {
+    str_shrink(path);
     RBASIC_SET_CLASS(path, rb_obj_class(orig));
     OBJ_FREEZE(path);
     return path;