To: vim-dev@vim.org
Subject: Patch 6.0.179 (extra)
Fcc: outbox
From: Bram Moolenaar <Bram@moolenaar.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
------------

Patch 6.0.179
Problem:    Win32: When displaying UTF-8 characters may read uninitialized
	    memory.
Solution:   Add utfc_ptr2len_check_len() to avoid reading past the end of a
	    string.
Files:	    src/mbyte.c, src/proto/mbyte.pro, src/gui_w32.c


*** ../vim60.178/src/mbyte.c	Sun Nov  4 14:31:23 2001
--- src/mbyte.c	Mon Feb  4 21:20:34 2002
***************
*** 1265,1270 ****
--- 1265,1308 ----
  }
  
  /*
+  * Return the number of bytes the UTF-8 encoding of the character at "p[size]"
+  * takes.  This includes following composing characters.
+  */
+     int
+ utfc_ptr2len_check_len(p, size)
+     char_u	*p;
+     int		size;
+ {
+     int		len;
+ 
+     if (*p == NUL)
+ 	return 0;
+     if (p[0] < 0x80 && (size == 1 || p[1] < 0x80)) /* be quick for ASCII */
+ 	return 1;
+ 
+     /* Skip over first UTF-8 char, stopping at a NUL byte. */
+     len = utf_ptr2len_check_len(p, size);
+ 
+     /* Check for illegal byte. */
+     if (len == 1 && p[0] >= 0x80)
+ 	return 1;
+ 
+     /*
+      * Check for composing characters.  We can handle only the first two, but
+      * skip all of them (otherwise the cursor would get stuck).
+      */
+     while (len < size)
+     {
+ 	if (p[len] < 0x80 || !utf_iscomposing(utf_ptr2char(p + len)))
+ 	    break;
+ 
+ 	/* Skip over composing char */
+ 	len += utf_ptr2len_check_len(p + len, size - len);
+     }
+     return len;
+ }
+ 
+ /*
   * Return the number of bytes the UTF-8 encoding of character "c" takes.
   * This does not include composing characters.
   */
*** ../vim60.178/src/proto/mbyte.pro	Sun Nov  4 14:31:23 2001
--- src/proto/mbyte.pro	Mon Feb  4 21:19:58 2002
***************
*** 24,29 ****
--- 24,30 ----
  int utf_byte2len __ARGS((int b));
  int utf_ptr2len_check_len __ARGS((char_u *p, int size));
  int utfc_ptr2len_check __ARGS((char_u *p));
+ int utfc_ptr2len_check_len __ARGS((char_u *p, int size));
  int utf_char2len __ARGS((int c));
  int utf_char2bytes __ARGS((int c, char_u *buf));
  int utf_iscomposing __ARGS((int c));
*** ../vim60.178/src/gui_w32.c	Sun Feb  3 12:33:39 2002
--- src/gui_w32.c	Mon Feb  4 21:19:20 2002
***************
*** 1807,1813 ****
  	    {
  		unicodebuf[clen] = utf_ptr2char(text + i);
  		cells += utf_char2cells(unicodebuf[clen]);
! 		i += utfc_ptr2len_check(text + i);
  		++clen;
  	    }
  	    ExtTextOutW(s_hdc, TEXT_X(col), TEXT_Y(row),
--- 1807,1813 ----
  	    {
  		unicodebuf[clen] = utf_ptr2char(text + i);
  		cells += utf_char2cells(unicodebuf[clen]);
! 		i += utfc_ptr2len_check_len(text + i, len - i);
  		++clen;
  	    }
  	    ExtTextOutW(s_hdc, TEXT_X(col), TEXT_Y(row),
*** ../vim60.178/src/version.c	Mon Feb  4 22:30:34 2002
--- src/version.c	Mon Feb  4 22:30:53 2002
***************
*** 608,609 ****
--- 608,611 ----
  {   /* Add new patch number below this line */
+ /**/
+     179,
  /**/

-- 
hundred-and-one symptoms of being an internet addict:
207. You're given one phone call in prison and you ask them for a laptop.

 ///  Bram Moolenaar -- Bram@moolenaar.net -- http://www.moolenaar.net  \\\
(((   Creator of Vim -- http://vim.sf.net -- ftp://ftp.vim.org/pub/vim   )))
 \\\  Help me helping AIDS orphans in Uganda - http://iccf-holland.org  ///