Raise ArgumentError for IO.foreach with limit of 0

Makes behavior consistent with IO.readlines.

Fixes [Bug #18767]

1 files changed, 2 insertions, 0 deletions

diff --git a/io.c b/io.c
index f2c64989df..1eb48dd19b 100644
--- a/io.c
+++ b/io.c
@@ -11518,6 +11518,8 @@ io_s_foreach(VALUE v)
     struct getline_arg *arg = (void *)v;
     VALUE str;
 
+    if (arg->limit == 0)
+        rb_raise(rb_eArgError, "invalid limit: 0 for foreach");
     while (!NIL_P(str = rb_io_getline_1(arg->rs, arg->limit, arg->chomp, arg->io))) {
         rb_lastline_set(str);
         rb_yield(str);