Added O_EXCL call to open is tmp == 1

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@378 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

ChangeLog

 CVS code -
+- files.c:
+  write_file()
+	- Added O_EXCL to open call if tmp is set, more security which hopefully
+	  fixes any remaining security issues.
+
 nano 0.9.22 - 12/02/2000
 - General
 	- Username tab completion code, and cleaned up existing tabcomp

files.c

@@ -335,10 +335,17 @@ int write_file(char *name, int tmp)
 	 return -1;
     else if (ISSET(FOLLOW_SYMLINKS) || !S_ISLNK(st.st_mode)) {
 
-	/* Open the file and truncate it.  Trust the symlink. */
-	if ((fd = open(realname, O_WRONLY | O_CREAT | O_TRUNC,
+	/* If tmp is set, use O_EXCL, more security, YAY! */
+	if (tmp)
+	    fd = open(realname, O_WRONLY | O_CREAT | O_EXCL | O_TRUNC,
+		       S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH |
+		       S_IWOTH);
+	else
+	    fd = open(realname, O_WRONLY | O_CREAT | O_TRUNC,
 		       S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH |
-		       S_IWOTH)) == -1) {
+		       S_IWOTH);
+	/* Open the file and truncate it.  Trust the symlink. */
+	if (fd == -1) {
 	    if (ISSET(TEMP_OPT)) {
 		UNSET(TEMP_OPT);
 		return do_writeout(1);