iotests: Test convert -n to pre-filled image

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-11-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

tests/qemu-iotests/122

@@ -257,6 +257,23 @@ for min_sparse in 4k 8k; do
     $QEMU_IMG map --output=json "$TEST_IMG".orig | _filter_qemu_img_map
 done
 
+
+echo
+echo '=== -n to a non-zero image ==='
+echo
+
+# Keep source zero
+_make_test_img 64M
+
+# Output is not zero, but has bdrv_has_zero_init() == 1
+TEST_IMG="$TEST_IMG".orig _make_test_img 64M
+$QEMU_IO -c "write -P 42 0 64k" "$TEST_IMG".orig | _filter_qemu_io
+
+# Convert with -n, which should not assume that the target is zeroed
+$QEMU_IMG convert -O $IMGFMT -n "$TEST_IMG" "$TEST_IMG".orig
+
+$QEMU_IMG compare "$TEST_IMG" "$TEST_IMG".orig
+
 # success, all done
 echo '*** done'
 rm -f $seq.full

tests/qemu-iotests/122.out

@@ -220,4 +220,12 @@ convert -c -S 8k
 { "start": 9216, "length": 8192, "depth": 0, "zero": true, "data": false},
 { "start": 17408, "length": 1024, "depth": 0, "zero": false, "data": true},
 { "start": 18432, "length": 67090432, "depth": 0, "zero": true, "data": false}]
+
+=== -n to a non-zero image ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+Formatting 'TEST_DIR/t.IMGFMT.orig', fmt=IMGFMT size=67108864
+wrote 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Images are identical.
 *** done