vmdk: Fix converting to streamOptimized

Commit d62d9dc lifted streamOptimized images's version to 3, but we
now refuse to open version 3 images read-write.  We need to make
streamOptimized an exception to allow converting to it. This fixes the
accidentally broken iotests case 059 for the same reason.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

block/vmdk.c

@@ -571,6 +571,7 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
     VmdkExtent *extent;
     BDRVVmdkState *s = bs->opaque;
     int64_t l1_backup_offset = 0;
+    bool compressed;
 
     ret = bdrv_pread(file->bs, sizeof(magic), &header, sizeof(header));
     if (ret < 0) {
@@ -645,14 +646,17 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
         header = footer.header;
     }
 
+    compressed =
+        le16_to_cpu(header.compressAlgorithm) == VMDK4_COMPRESSION_DEFLATE;
     if (le32_to_cpu(header.version) > 3) {
         char buf[64];
         snprintf(buf, sizeof(buf), "VMDK version %" PRId32,
                  le32_to_cpu(header.version));
         error_setg(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
                    bdrv_get_device_or_node_name(bs), "vmdk", buf);
         return -ENOTSUP;
-    } else if (le32_to_cpu(header.version) == 3 && (flags & BDRV_O_RDWR)) {
+    } else if (le32_to_cpu(header.version) == 3 && (flags & BDRV_O_RDWR) &&
+               !compressed) {
         /* VMware KB 2064959 explains that version 3 added support for
          * persistent changed block tracking (CBT), and backup software can
          * read it as version=1 if it doesn't care about the changed area