[PULL 10/34] qga: Fix guest-get-fsinfo error API violations

[Markus Armbruster]

build_guest_fsinfo_for_virtual_device() dereferences @errp when
build_guest_fsinfo_for_device() fails.  That's wrong; see the big
comment in error.h.  Introduced in commit 46d4c5723e "qga: Add
guest-get-fsinfo command".

No caller actually passes null.

Fix anyway: splice in a local Error *err, and error_propagate().

Cc: Michael Roth <mdr...@linux.vnet.ibm.com>
Signed-off-by: Markus Armbruster <arm...@redhat.com>
Message-Id: <20191204093625.14836-10-arm...@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
 qga/commands-posix.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 0be301a4ea..10d818c3b2 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -1060,6 +1060,7 @@ static void build_guest_fsinfo_for_virtual_device(char 
const *syspath,
                                                   GuestFilesystemInfo *fs,
                                                   Error **errp)
 {
+    Error *err = NULL;
     DIR *dir;
     char *dirpath;
     struct dirent *entry;
@@ -1089,10 +1090,11 @@ static void build_guest_fsinfo_for_virtual_device(char 
const *syspath,
 
             g_debug(" slave device '%s'", entry->d_name);
             path = g_strdup_printf("%s/slaves/%s", syspath, entry->d_name);
-            build_guest_fsinfo_for_device(path, fs, errp);
+            build_guest_fsinfo_for_device(path, fs, &err);
             g_free(path);
 
-            if (*errp) {
+            if (err) {
+                error_propagate(errp, err);
                 break;
             }
         }
-- 
2.21.0