fixed --test on zero-length files, reported by @amnilsson
diff --git a/programs/playTests.sh b/programs/playTests.sh
index 7550608..ef44f7b 100755
--- a/programs/playTests.sh
+++ b/programs/playTests.sh
@@ -209,6 +209,8 @@
 $ZSTD -t tmp1 && die "bad file not detected !"
 cp tmp1 tmp2.zst
 $ZSTD -t tmp2.zst && die "bad file not detected !"
+./datagen -g0 > tmp3
+$ZSTD -t tmp3 && die "bad file not detected !"   # detects 0-sized files as bad
 $ECHO "test --rm and --test combined "
 $ZSTD -t --rm tmp1.zst
 ls -ls tmp1.zst  # check file is still present