[PATCH 12/21] qga: Fix latent guest-get-fsinfo error handling bug

[Markus Armbruster <armbru@redhat.com>]

build_guest_fsinfo_for_virtual_device() crashes when
build_guest_fsinfo_for_device() fails and its @errp argument is null.
Messed up in commit 46d4c5723e "qga: Add guest-get-fsinfo command".

The bug can't bite as no caller actually passes null.  Fix it anyway.

Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.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 1c1a165dae..0be527ccb8 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -1049,6 +1049,7 @@ 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;
@@ -1078,10 +1079,11 @@ 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