[libvirt] [libvirt-sandbox PATCH] sandbox-builder: Don't try g_file_enumerator_next_file if enumerator is NULL

[Guido Günther]

Passing the NULL enumerator to g_file_enumerator_next_file makes
us overwrite error information otherwise:

    $ sudo bin/virt-sandbox-service create --unitfile foo.service foo
    (process:18529): GLib-GIO-CRITICAL **: g_file_enumerator_next_file: assertion 'G_IS_FILE_ENUMERATOR (enumerator)' failed

    (process:18529): GLib-GIO-CRITICAL **: g_file_enumerator_close: assertion 'G_IS_FILE_ENUMERATOR (enumerator)' failed
    bin/virt-sandbox-service:318: Warning: GError set over the top of a previous GError or uninitialized memory.
    This indicates a bug in someone's code. You must ensure an error is NULL before it's set.
    The overwriting error message was: Error removing file: No such file or directory context.undefine()
    bin/virt-sandbox-service:318: Warning: g_object_unref: assertion 'G_IS_OBJECT (object)' failed context.undefine()
    Cleanup failed: g-io-error-quark: No such file or directory (1)
    bin/virt-sandbox-service: g-io-error-quark: No such file or directory (1)

also make sure we don't unref NULL in this case.
---
 libvirt-sandbox/libvirt-sandbox-builder.c | 37 +++++++++++++++++--------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/libvirt-sandbox/libvirt-sandbox-builder.c b/libvirt-sandbox/libvirt-sandbox-builder.c
index 1745c88..0c43b62 100644
--- a/libvirt-sandbox/libvirt-sandbox-builder.c
+++ b/libvirt-sandbox/libvirt-sandbox-builder.c
@@ -727,32 +727,35 @@ gboolean gvir_sandbox_builder_clean_post_stop(GVirSandboxBuilder *builder,
         errno != ENOENT)
         ret = FALSE;
 
-    if (!(enumerator = g_file_enumerate_children(libsFile, "*", G_FILE_QUERY_INFO_NONE,
-                                                 NULL, error)) &&
-        (*error)->code != G_IO_ERROR_NOT_FOUND) {
-        ret = FALSE;
-        goto cleanup;
-    }
+    if ((enumerator = g_file_enumerate_children(libsFile, "*", G_FILE_QUERY_INFO_NONE,
+                                               NULL, error))) {
+        while ((info = g_file_enumerator_next_file(enumerator, NULL, error))) {
+            child = g_file_enumerator_get_child(enumerator, info);
+            if (!g_file_delete(child, NULL, error))
+                ret = FALSE;
+            g_object_unref(child);
+            child = NULL;
+            g_object_unref(info);
+            info = NULL;
+        }
 
-    while ((info = g_file_enumerator_next_file(enumerator, NULL, error))) {
-        child = g_file_enumerator_get_child(enumerator, info);
-        if (!g_file_delete(child, NULL, error))
+        if (!g_file_enumerator_close(enumerator, NULL, error))
+            ret = FALSE;
+    } else {
+        if ((*error)->code != G_IO_ERROR_NOT_FOUND) {
             ret = FALSE;
-        g_object_unref(child);
-        child = NULL;
-        g_object_unref(info);
-        info = NULL;
+            goto cleanup;
+        }
+        g_clear_error(error);
     }
 
-    if (!g_file_enumerator_close(enumerator, NULL, error))
-        ret = FALSE;
-
     if (!g_file_delete(libsFile, NULL, error) &&
         (*error)->code != G_IO_ERROR_NOT_FOUND)
         ret = FALSE;
 
  cleanup:
-    g_object_unref(enumerator);
+    if (enumerator)
+        g_object_unref(enumerator);
     g_object_unref(libsFile);
     g_free(libsdir);
     g_free(dskfile);
-- 
2.7.0