diff --git a/7.3.166 b/7.3.166
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+To: vim_dev@googlegroups.com
+Subject: Patch 7.3.166
+Fcc: outbox
+From: Bram Moolenaar <Bram@moolenaar.net>
+Mime-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+------------
+
+Patch 7.3.166
+Problem:    Buffer on the stack may be too big
+Solution:   Allocate the space.
+Files:	    src/option.c
+
+
+*** ../vim-7.3.165/src/option.c	2011-04-28 12:56:57.000000000 +0200
+--- src/option.c	2011-04-15 20:49:54.000000000 +0200
+***************
+*** 9185,9191 ****
+      int		expand;
+  {
+      char_u	*s;
+!     char_u	buf[MAXPATHL];
+  
+      if (fprintf(fd, "%s %s=", cmd, name) < 0)
+  	return FAIL;
+--- 9185,9191 ----
+      int		expand;
+  {
+      char_u	*s;
+!     char_u	*buf;
+  
+      if (fprintf(fd, "%s %s=", cmd, name) < 0)
+  	return FAIL;
+***************
+*** 9203,9211 ****
+--- 9203,9218 ----
+  	}
+  	else if (expand)
+  	{
++ 	    buf = alloc(MAXPATHL);
++ 	    if (buf == NULL)
++ 		return FAIL;
+  	    home_replace(NULL, *valuep, buf, MAXPATHL, FALSE);
+  	    if (put_escstr(fd, buf, 2) == FAIL)
++ 	    {
++ 		vim_free(buf);
+  		return FAIL;
++ 	    }
++ 	    vim_free(buf);
+  	}
+  	else if (put_escstr(fd, *valuep, 2) == FAIL)
+  	    return FAIL;
+*** ../vim-7.3.165/src/version.c	2011-04-28 17:21:49.000000000 +0200
+--- src/version.c	2011-04-28 17:23:24.000000000 +0200
+***************
+*** 716,717 ****
+--- 716,719 ----
+  {   /* Add new patch number below this line */
++ /**/
++     166,
+  /**/
+
+-- 
+He who laughs last, thinks slowest.
+
+ /// Bram Moolenaar -- Bram@Moolenaar.net -- http://www.Moolenaar.net   \\\
+///        sponsor Vim, vote for features -- http://www.Vim.org/sponsor/ \\\
+\\\  an exciting new programming language -- http://www.Zimbu.org        ///
+ \\\            help me help AIDS victims -- http://ICCF-Holland.org    ///