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 <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 memory_mapping.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/memory_mapping.c b/memory_mapping.c
index 18d0b8067c..d95df2484b 100644
--- a/memory_mapping.c
+++ b/memory_mapping.c
@@ -288,6 +288,7 @@ void qemu_get_guest_memory_mapping(MemoryMappingList *list,
                                    const GuestPhysBlockList *guest_phys_blocks,
                                    Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     CPUState *cpu, *first_paging_enabled_cpu;
     GuestPhysBlock *block;
     ram_addr_t offset, length;
@@ -296,10 +297,8 @@ void qemu_get_guest_memory_mapping(MemoryMappingList *list,
     if (first_paging_enabled_cpu) {
         for (cpu = first_paging_enabled_cpu; cpu != NULL;
              cpu = CPU_NEXT(cpu)) {
-            Error *err = NULL;
-            cpu_get_memory_mapping(cpu, list, &err);
-            if (err) {
-                error_propagate(errp, err);
+            cpu_get_memory_mapping(cpu, list, errp);
+            if (*errp) {
                 return;
             }
         }
-- 
2.21.0