Fix out-of-bound access
Get rid of out-of-bound access when single % at the end.
MODIFY
mrbgems/mruby-sprintf/src/sprintf.c
mrbgems/mruby-sprintf/src/sprintf.c
@@ -567,6 +567,7 @@ mrb_str_format(mrb_state *mrb, int argc, const mrb_value *argv, mrb_value fmt)
mrb_sym id = 0;
for (t = p; t < end && *t != '%'; t++) ;
+ if (t + 1 == end) ++t;
PUSH(p, t - p);
if (t >= end)
goto sprint_exit; /* end of fmt string */

MODIFY
mrbgems/mruby-sprintf/test/sprintf.rb
mrbgems/mruby-sprintf/test/sprintf.rb
@@ -30,3 +30,14 @@ assert("String#% with invalid chr") do
end
end
end
+
+assert("String#% invalid format") do
+ assert_raise ArgumentError do
+ "%?" % ""
+ end
+end
+
+assert("String#% invalid format shared substring") do
+ fmt = ("x"*30+"%!")[0...-1]
+ assert_equal fmt, sprintf(fmt, "")
+end

Fix out-of-bound access

Get rid of out-of-bound access when single % at the end.