win32: use ALLOCV

* win32/file.c (rb_readlink): use ALLOCV to get rid potential
  memory leak by NoMemoryError in ALLOCV.

* win32/win32.c (w32_readlink): allocate WCHAR path name and
  reparse buffer together.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51737 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

win32/file.c

@@ -663,7 +663,7 @@ VALUE
 rb_readlink(VALUE path)
 {
     DWORD len;
-    VALUE wtmp = 0, str;
+    VALUE wtmp = 0, wpathbuf, str;
     rb_w32_reparse_buffer_t rbuf, *rp = &rbuf;
     WCHAR *wpath, *wbuf;
     rb_encoding *enc;
@@ -677,16 +677,17 @@ rb_readlink(VALUE path)
 	path = fix_string_encoding(path, enc);
 	cp = CP_UTF8;
     }
-    wpath = mbstr_to_wstr(cp, RSTRING_PTR(path),
-			  RSTRING_LEN(path)+rb_enc_mbminlen(enc), NULL);
-    if (!wpath) rb_memerror();
+    len = MultiByteToWideChar(cp, 0, RSTRING_PTR(path), RSTRING_LEN(path), NULL, 0);
+    wpath = ALLOCV_N(WCHAR, wpathbuf, len+1);
+    MultiByteToWideChar(cp, 0, RSTRING_PTR(path), RSTRING_LEN(path), wpath, len);
+    wpath[len] = L'\0';
     e = rb_w32_read_reparse_point(wpath, rp, sizeof(rbuf), &wbuf, &len);
     if (e == ERROR_MORE_DATA) {
 	size_t size = rb_w32_reparse_buffer_size(len + 1);
 	rp = ALLOCV(wtmp, size);
 	e = rb_w32_read_reparse_point(wpath, rp, size, &wbuf, &len);
     }
-    free(wpath);
+    ALLOCV_END(wpathbuf);
     if (e) {
 	ALLOCV_END(wtmp);
 	rb_syserr_fail_path(rb_w32_map_errno(e), path);

win32/win32.c

@@ -4813,27 +4813,23 @@ rb_w32_read_reparse_point(const WCHAR *path, rb_w32_reparse_buffer_t *rp,
 static ssize_t
 w32_readlink(UINT cp, const char *path, char *buf, size_t bufsize)
 {
-    WCHAR *wpath, *wname;
     VALUE wtmp;
-    size_t size = rb_w32_reparse_buffer_size(bufsize);
-    rb_w32_reparse_buffer_t *rp = ALLOCV(wtmp, size);
-    DWORD len;
+    DWORD len = MultiByteToWideChar(cp, 0, path, -1, NULL, 0);
+    size_t size = rb_w32_reparse_buffer_size(len);
+    WCHAR *wname, *wpath = ALLOCV(wtmp, size + sizeof(WCHAR) * len);
+    rb_w32_reparse_buffer_t *rp = (void *)(wpath + len);
     ssize_t ret;
     int e;
 
-    wpath = mbstr_to_wstr(cp, path, -1, NULL);
-    if (!wpath) {
-	ALLOCV_END(wtmp);
-	return -1;
-    }
+    MultiByteToWideChar(cp, 0, path, -1, wpath, len);
     e = rb_w32_read_reparse_point(wpath, rp, size, &wname, &len);
-    free(wpath);
     if (e && e != ERROR_MORE_DATA) {
 	ALLOCV_END(wtmp);
 	errno = map_errno(e);
 	return -1;
     }
     ret = WideCharToMultiByte(cp, 0, wname, len, buf, bufsize, NULL, NULL);
+    ALLOCV_END(wtmp);
     if (e) {
 	ret = bufsize;
     }