* string.c (rb_str_modify_expand): fix memory leak.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@34492 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Wed Feb  8 22:29:59 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (rb_str_modify_expand): fix memory leak.
+
 Wed Feb  8 14:06:59 2012  Hiroshi Nakamura  <nahi@ruby-lang.org>
 
 	* ext/openssl/ossl_ssl.c: Add SSL constants and allow to unset SSL

ext/-test-/string/modify.c

@@ -7,8 +7,16 @@ bug_str_modify(VALUE str)
     return str;
 }
 
+VALUE
+bug_str_modify_expand(VALUE str, VALUE expand)
+{
+    rb_str_modify_expand(str, NUM2LONG(expand));
+    return str;
+}
+
 void
 Init_modify(VALUE klass)
 {
     rb_define_method(klass, "modify!", bug_str_modify, 0);
+    rb_define_method(klass, "modify_expand!", bug_str_modify_expand, 1);
 }

include/ruby/intern.h

@@ -712,6 +712,7 @@ long rb_str_sublen(VALUE, long);
 VALUE rb_str_substr(VALUE, long, long);
 VALUE rb_str_subseq(VALUE, long, long);
 void rb_str_modify(VALUE);
+void rb_str_modify_expand(VALUE, long);
 VALUE rb_str_freeze(VALUE);
 void rb_str_set_len(VALUE, long);
 VALUE rb_str_resize(VALUE, long);

string.c

@@ -1328,12 +1328,20 @@ rb_str_modify_expand(VALUE str, long expand)
     if (expand < 0) {
 	rb_raise(rb_eArgError, "negative expanding string size");
     }
-    if (!str_independent(str) ||
-	(expand > 0 &&
-	 (!STR_EMBED_P(str) ||
-	  RSTRING_LEN(str) + expand > RSTRING_EMBED_LEN_MAX))) {
+    if (!str_independent(str)) {
 	str_make_independent_expand(str, expand);
     }
+    else if (expand > 0) {
+	long len = RSTRING_LEN(str);
+	long capa = len + expand;
+	if (!STR_EMBED_P(str)) {
+	    REALLOC_N(RSTRING(str)->as.heap.ptr, char, capa+1);
+	    RSTRING(str)->as.heap.aux.capa = capa;
+	}
+	else if (capa > RSTRING_EMBED_LEN_MAX) {
+	    str_make_independent_expand(str, expand);
+	}
+    }
     ENC_CODERANGE_CLEAR(str);
 }