patch 8.0.0298: Ex command range with repeated search does not work

Problem:    Ex command range with repeated search does not work. (Bruce
            DeVisser)
Solution:   Skip over \/, \? and \&.
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index f93c766..3ee7056 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -4357,9 +4357,16 @@
 {
     unsigned	delim;
 
-    while (vim_strchr((char_u *)" \t0123456789.$%'/?-+,;", *cmd) != NULL)
+    while (vim_strchr((char_u *)" \t0123456789.$%'/?-+,;\\", *cmd) != NULL)
     {
-	if (*cmd == '\'')
+	if (*cmd == '\\')
+	{
+	    if (cmd[1] == '?' || cmd[1] == '/' || cmd[1] == '&')
+		++cmd;
+	    else
+		break;
+	}
+	else if (*cmd == '\'')
 	{
 	    if (*++cmd == NUL && ctx != NULL)
 		*ctx = EXPAND_NOTHING;