# HG changeset patch
# User Kim Alvefur <zash@zash.se>
# Date 1590768702 -7200
# Node ID c6465fb3c839174d0e655011eece503db10f8783
# Parent  37df1e757f02cdbec815b8540e5b76a15a1ea79c
util.ringbuffer: Prevent creation of zero-size buffer

diff -r 37df1e757f02 -r c6465fb3c839 spec/util_ringbuffer_spec.lua
--- a/spec/util_ringbuffer_spec.lua	Fri May 29 17:53:00 2020 +0200
+++ b/spec/util_ringbuffer_spec.lua	Fri May 29 18:11:42 2020 +0200
@@ -7,6 +7,11 @@
 		it("can be created", function ()
 			assert.truthy(rb.new());
 		end);
+		it("won't create an empty buffer", function ()
+			assert.has_error(function ()
+				rb.new(0);
+			end);
+		end);
 	end);
 	describe(":write", function ()
 		local b = rb.new();
diff -r 37df1e757f02 -r c6465fb3c839 util-src/ringbuffer.c
--- a/util-src/ringbuffer.c	Fri May 29 17:53:00 2020 +0200
+++ b/util-src/ringbuffer.c	Fri May 29 18:11:42 2020 +0200
@@ -198,6 +198,7 @@
 
 static int rb_new(lua_State *L) {
 	size_t size = luaL_optinteger(L, 1, sysconf(_SC_PAGESIZE));
+	luaL_argcheck(L, size > 0, 1, "positive integer expected");
 	ringbuffer *b = lua_newuserdata(L, sizeof(ringbuffer) + size);
 
 	b->rpos = 0;