[glib: 1/2] trash portal: Fix permission checks

[Philip Withnall <pwithnall src gnome org>]

commit 147ac51f902fc2a6b6e98e823ea0bf7058ce0f8d
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Mar 4 19:47:11 2019 +0000

    trash portal: Fix permission checks
    
    Implement the approach suggested in
    https://gitlab.gnome.org/GNOME/glib/merge_requests/276
    
    1. Try to open O_RDWR. On success, pass that fd
    2. If EACCESS => fail the trash op, we "need" read-write to successfully trash it
    3. If EISDIR => re-open the fd with O_PATH, and pass that (which will fail on snap,
       but verify the dir for flatpaks)

 gio/gtrashportal.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)
---
diff --git a/gio/gtrashportal.c b/gio/gtrashportal.c
index a1e82102b..b6aca37a6 100644
--- a/gio/gtrashportal.c
+++ b/gio/gtrashportal.c
@@ -37,6 +37,10 @@
 #define HAVE_O_CLOEXEC 1
 #endif
 
+#ifndef O_PATH
+#define O_PATH 0
+#endif
+
 static GXdpTrash *
 ensure_trash_portal (void)
 {
@@ -83,9 +87,9 @@ g_trash_portal_trash_file (GFile   *file,
   path = g_file_get_path (file);
 
   fd = g_open (path, O_RDWR | O_CLOEXEC);
-  if (fd == -1 && (errno == EACCES || errno == EISDIR))
-    /* If we don't have write access, fall back to read-only */
-    fd = g_open (path, O_CLOEXEC | O_RDONLY);
+  if (fd == -1 && errno == EISDIR)
+    /* If it is a directory, fall back to O_PATH */
+    fd = g_open (path, O_PATH | O_CLOEXEC | O_RDONLY);
 
   errsv = errno;