Making str::from_cstr UTF-8 safe

Author: killerswan

src/libcore/str.rs

@@ -217,16 +217,16 @@ Function: from_cstr
 Create a Rust string from a null-terminated C string
 */
 unsafe fn from_cstr(cstr: sbuf) -> str {
-    let res = "";
+    let res = [];
     let start = cstr;
     let curr = start;
     let i = 0u;
     while *curr != 0u8 {
-        push_byte(res, *curr);
+        vec::push(res, *curr);
         i += 1u;
         curr = ptr::offset(start, i);
     }
-    ret res;
+    ret from_bytes(res);
 }
 
 /*