commit 989f592f7ffcbafdc4ec35cee4dc65bd053e2077
author Bram Moolenaar <Bram@vim.org> Sun Aug 21 15:26:54 2016 +0200
committer Bram Moolenaar <Bram@vim.org> Sun Aug 21 15:26:54 2016 +0200
tree 122c18af5dbbd1b69e025a7d0293ff0b55e4a93b
parent dd1248143e56b1450903fe40813e40c63691b071

patch 7.4.2235
Problem:    submatch() does not check for a valid argument.
Solution:   Give an error if the argument is out of range. (Dominique Pelle)

src/evalfunc.c

diff --git a/src/evalfunc.c b/src/evalfunc.c
index 53d3d75..599a3d6 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -11491,7 +11491,11 @@
     no = (int)get_tv_number_chk(&argvars[0], &error);
     if (error)
 	return;
-    error = FALSE;
+    if (no < 0 || no >= NSUBEXP)
+    {
+        EMSGN(_("E935: invalid submatch number: %d"), no);
+        return;
+    }
     if (argvars[1].v_type != VAR_UNKNOWN)
 	retList = (int)get_tv_number_chk(&argvars[1], &error);
     if (error)