util.format: Handle integer formats the same way on Lua versions without integer support

2 files changed, 6 insertions, 2 deletions

diff --git a/spec/util_format_spec.lua b/spec/util_format_spec.lua
index 82b70205..50509630 100644
--- a/spec/util_format_spec.lua
+++ b/spec/util_format_spec.lua
@@ -13,6 +13,7 @@ describe("util.format", function()
 			assert.equal("% [true]", format("%%", true));
 			assert.equal("{ }", format("%q", { }));
 			assert.equal("[1.5]", format("%d", 1.5));
+			assert.equal("[7.3786976294838e+19]", format("%d", 73786976294838206464));
 		end);
 	end);
 end);
diff --git a/util/format.lua b/util/format.lua
index 857bb694..1ce670f3 100644
--- a/util/format.lua
+++ b/util/format.lua
@@ -7,9 +7,12 @@ local unpack = table.unpack or unpack; -- luacheck: ignore 113/unpack
 local pack = require "util.table".pack; -- TODO table.pack in 5.2+
 local type = type;
 local dump = require "util.serialization".new("debug");
-local num_type = math.type;
+local num_type = math.type or function (n)
+	return n % 1 == 0 and n <= 9007199254740992 and n >= -9007199254740992 and "integer" or "float";
+end
 
-local expects_integer = num_type and { c = true, d = true, i = true, o = true, u = true, X = true, x = true, } or {};
+-- In Lua 5.3+ these formats throw an error if given a float
+local expects_integer = { c = true, d = true, i = true, o = true, u = true, X = true, x = true, };
 
 local function format(formatstring, ...)
 	local args = pack(...);