updated for version 7.4b.006
Problem:    Using \{n,m} in an autocommand pattern no longer works.
            Specifically, mutt temp files are not recognized. (Gary Johnson)
Solution:   Make \\\{n,m\} work.
diff --git a/src/fileio.c b/src/fileio.c
index fe90246..731a7b1 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -10327,7 +10327,7 @@
 		 * Don't unescape \, * and others that are also special in a
 		 * regexp.
 		 * An escaped { must be unescaped since we use magic not
-		 * verymagic.
+		 * verymagic.  Use "\\\{n,m\}"" to get "\{n,m}".
 		 */
 		if (*++p == '?'
 #ifdef BACKSLASH_IN_FILENAME
@@ -10337,8 +10337,14 @@
 		    reg_pat[i++] = '?';
 		else
 		    if (*p == ',' || *p == '%' || *p == '#'
-						    || *p == ' ' || *p == '{')
+				       || *p == ' ' || *p == '{' || *p == '}')
 			reg_pat[i++] = *p;
+		    else if (*p == '\\' && p[1] == '\\' && p[2] == '{')
+		    {
+			reg_pat[i++] = '\\';
+			reg_pat[i++] = '{';
+			p += 2;
+		    }
 		    else
 		    {
 			if (allow_dirs != NULL && vim_ispathsep(*p)