[RFC v5 125/126] tests/test-image-locking.c: introduce ERRP_AUTO_PROPAGATE

[Vladimir Sementsov-Ogievskiy]

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
Otherwise, this info will not be added when errp == &fatal_err
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix such cases.

If we want to check error after errp-function call, we need to
introduce local_err and than propagate it to errp. Instead, use
ERRP_AUTO_PROPAGATE macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_AUTO_PROPAGATE leaves errp as is if it's not NULL or
   &error_fatel, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

This commit (together with its neighbors) was generated by

for f in $(git grep -l errp \*.[ch]); do \
    spatch --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
    --macro-file scripts/cocci-macro-file.h --in-place --no-show-diff $f; \
done;

then fix a bit of compilation problems: coccinelle for some reason
leaves several
f() {
    ...
    goto out;
    ...
    out:
}
patterns, with "out:" at function end.

then
./python/commit-per-subsystem.py MAINTAINERS "$(< auto-msg)"

(auto-msg was a file with this commit message)

Still, for backporting it may be more comfortable to use only the first
command and then do one huge commit.

Reported-by: Kevin Wolf <address@hidden>
Reported-by: Greg Kurz <address@hidden>
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
 tests/test-image-locking.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/tests/test-image-locking.c b/tests/test-image-locking.c
index ba057bd66c..4c996bdf55 100644
--- a/tests/test-image-locking.c
+++ b/tests/test-image-locking.c
@@ -35,20 +35,19 @@ static BlockBackend *open_image(const char *path,
                                 uint64_t perm, uint64_t shared_perm,
                                 Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     BlockBackend *blk;
     QDict *options = qdict_new();
 
     qdict_put_str(options, "driver", "raw");
-    blk = blk_new_open(path, NULL, options, BDRV_O_RDWR, &local_err);
+    blk = blk_new_open(path, NULL, options, BDRV_O_RDWR, errp);
     if (blk) {
-        g_assert_null(local_err);
+        g_assert_null(*errp);
         if (blk_set_perm(blk, perm, shared_perm, errp)) {
             blk_unref(blk);
             blk = NULL;
         }
     } else {
-        error_propagate(errp, local_err);
     }
     return blk;
 }
-- 
2.21.0