[gnome-desktop] thumbnail: Resolve symlinks before exporting them with Flatpak

[Michael Catanzaro <mcatanzaro src gnome org>]

commit fbb3e9d20b226bf894ee86b29037a9924d96a16f
Author: Ryan Gonzalez <ryan gonzalez collabora com>
Date:   Tue Feb 1 12:13:47 2022 -0600

    thumbnail: Resolve symlinks before exporting them with Flatpak
    
    Otherwise, only the symlink target is sent into the sandbox, so the symlink
    itself is not found, and thumbnailing fails.
    
    Signed-off-by: Ryan Gonzalez <ryan gonzalez collabora com>

 libgnome-desktop/gnome-desktop-thumbnail-script.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
---
diff --git a/libgnome-desktop/gnome-desktop-thumbnail-script.c 
b/libgnome-desktop/gnome-desktop-thumbnail-script.c
index 841ca17d..b6c31e93 100644
--- a/libgnome-desktop/gnome-desktop-thumbnail-script.c
+++ b/libgnome-desktop/gnome-desktop-thumbnail-script.c
@@ -984,6 +984,20 @@ script_exec_new (const char  *uri,
     {
       char *tmpl;
       const char *sandbox_dir;
+      g_autofree char *resolved_infile = NULL;
+
+      /* Make sure any symlinks in the path are resolved, because the resolved
+       * path is what's exposed by Flatpak into the sandbox */
+      resolved_infile = realpath (exec->infile, NULL);
+      if (!resolved_infile)
+        {
+          g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),
+                       "Failed to resolve '%s': '%s'", exec->infile, g_strerror (errno));
+          goto bail;
+        }
+
+      g_free (exec->infile);
+      exec->infile = g_steal_pointer (&resolved_infile);
 
       sandbox_dir = g_getenv ("FLATPAK_SANDBOX_DIR");
       if (!sandbox_dir || *sandbox_dir != '/')