[ruby/zlib] In Zlib::GzipReader#eof? check if we're actually at eof

Only consider it eof if we read ahead and something fills the buf.
If not, we may only have empty blocks and the footer.

Fixes https://github.com/ruby/zlib/pull/56

https://github.com/ruby/zlib/commit/437bea8003

1 files changed, 3 insertions, 0 deletions

diff --git a/ext/zlib/zlib.c b/ext/zlib/zlib.c
index dc608ee460..fe03072576 100644
--- a/ext/zlib/zlib.c
+++ b/ext/zlib/zlib.c
@@ -3500,6 +3500,9 @@ static VALUE
 rb_gzfile_eof_p(VALUE obj)
 {
     struct gzfile *gz = get_gzfile(obj);
+    while (!ZSTREAM_IS_FINISHED(&gz->z) && ZSTREAM_BUF_FILLED(&gz->z) == 0) {
+	gzfile_read_more(gz, Qnil);
+    }
     return GZFILE_IS_FINISHED(gz) ? Qtrue : Qfalse;
 }