file: guard against recursive links when emitting change signals

Currently, when propagating file changes, the code recursively notifies
the files that link to the original file. This quickly falls apart with
recursive links, as a stack overflow occurs. The fix is only partial,
however, in that if you try a bit harder, you can still crash Nautilus
by throwing in another file into the loop (hah).

Fixes https://gitlab.gnome.org/GNOME/nautilus/issues/289

1 files changed, 21 insertions, 2 deletions

diff --git a/src/nautilus-file.c b/src/nautilus-file.c
index 37f189f8c..5865c3229 100644
--- a/src/nautilus-file.c
+++ b/src/nautilus-file.c
@@ -8581,10 +8581,29 @@ nautilus_file_emit_changed (NautilusFile *file)
     link_files = get_link_files (file);
     for (p = link_files; p != NULL; p = p->next)
     {
-        if (p->data != file)
+        /* Looking for directly recursive links. */
+        g_autolist (NautilusFile) link_targets = NULL;
+        NautilusDirectory *directory;
+
+        if (p->data == file)
+        {
+            continue;
+        }
+
+        link_targets = get_link_files (p->data);
+        directory = nautilus_file_get_directory (p->data);
+
+        /* Reiterating (heh) that this will break with more complex cycles.
+         * Users, stop trying to break things on purpose.
+         */
+        if (g_list_find (link_targets, file) != NULL &&
+            directory == nautilus_file_get_directory (file))
         {
-            nautilus_file_changed (NAUTILUS_FILE (p->data));
+            g_signal_emit (p->data, signals[CHANGED], 0, p->data);
+            continue;
         }
+
+        nautilus_file_changed (NAUTILUS_FILE (p->data));
     }
     nautilus_file_list_free (link_files);
 }