From: Bram Moolenaar <Bram@vim.org>
Date: Tue, 25 May 2010 20:09:21 +0000 (+0200)
Subject: Fix for using ":wundo foo" when foo is an empty file.
X-Git-Tag: v7.3~350
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=83ad0147c02606ad1d32f62e84b65402bca9efec;p=vim

Fix for using ":wundo foo" when foo is an empty file.
---

diff --git a/src/undo.c b/src/undo.c
index 35fa31064..787f62590 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -1286,11 +1286,12 @@ u_write_undo(name, forceit, buf, hash)
 	    }
 	    else
 	    {
-		char_u buf[2];
+		char_u	buf[2];
+		int	len;
 
-		vim_read(fd, buf, 2);
+		len = vim_read(fd, buf, 2);
 		close(fd);
-		if ((buf[0] << 8) + buf[1] != UF_START_MAGIC)
+		if (len < 2 || (buf[0] << 8) + buf[1] != UF_START_MAGIC)
 		{
 		    if (name != NULL || p_verbose > 0)
 			smsg((char_u *)_("Will not overwrite, this is not an undo file: %s"),