diff options
Diffstat (limited to 'ext/stringio/stringio.c')
| -rw-r--r-- | ext/stringio/stringio.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c index bc605da2a7..9bb5ed8a2a 100644 --- a/ext/stringio/stringio.c +++ b/ext/stringio/stringio.c @@ -744,8 +744,37 @@ strio_ungetc(VALUE self, VALUE c) static VALUE strio_ungetbyte(VALUE self, VALUE c) { - NUM2INT(c); - return strio_ungetc(self, c); + struct StringIO *ptr = readable(StringIO(self)); + char buf[1], *cp = buf; + long pos = ptr->pos, cl = 1; + VALUE str = ptr->string; + + if (NIL_P(c)) return Qnil; + if (FIXNUM_P(c)) { + buf[0] = (char)FIX2INT(c); + } + else { + SafeStringValue(c); + cp = RSTRING_PTR(c); + cl = RSTRING_LEN(c); + if (cl == 0) return Qnil; + } + rb_str_modify(str); + if (cl > pos) { + char *s; + long rest = RSTRING_LEN(str) - pos; + rb_str_resize(str, rest + cl); + s = RSTRING_PTR(str); + memmove(s + cl, s + pos, rest); + pos = 0; + } + else { + pos -= cl; + } + memcpy(RSTRING_PTR(str) + pos, cp, cl); + ptr->pos = pos; + RB_GC_GUARD(c); + return Qnil; } /* |