qapi: Use QAPI_LIST_PREPEND() where possible

Anywhere we create a list of just one item or by prepending items
(typically because order doesn't matter), we can use
QAPI_LIST_PREPEND().  But places where we must keep the list in order
by appending remain open-coded until later patches.

Note that as a side effect, this also performs a cleanup of two minor
issues in qga/commands-posix.c: the old code was performing
 new = g_malloc0(sizeof(*ret));
which 1) is confusing because you have to verify whether 'new' and
'ret' are variables with the same type, and 2) would conflict with C++
compilation (not an actual problem for this file, but makes
copy-and-paste harder).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20201113011340.463563-5-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
[Straightforward conflicts due to commit a8aa94b5f8 "qga: update
schema for guest-get-disks 'dependents' field" and commit a10b453a52
"target/mips: Move mips_cpu_add_definition() from helper.c to cpu.c"
resolved.  Commit message tweaked.]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/qemu-img.c b/qemu-img.c
index 8bdea40b58..d599659c7f 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1652,14 +1652,13 @@ static void do_dirty_bitmap_merge(const char *dst_node, const char *dst_name,
                                   Error **errp)
 {
     BlockDirtyBitmapMergeSource *merge_src;
-    BlockDirtyBitmapMergeSourceList *list;
+    BlockDirtyBitmapMergeSourceList *list = NULL;
 
     merge_src = g_new0(BlockDirtyBitmapMergeSource, 1);
     merge_src->type = QTYPE_QDICT;
     merge_src->u.external.node = g_strdup(src_node);
     merge_src->u.external.name = g_strdup(src_name);
-    list = g_new0(BlockDirtyBitmapMergeSourceList, 1);
-    list->value = merge_src;
+    QAPI_LIST_PREPEND(list, merge_src);
     qmp_block_dirty_bitmap_merge(dst_node, dst_name, list, errp);
     qapi_free_BlockDirtyBitmapMergeSourceList(list);
 }