lib: break reference loop by choosing arbitrary top level msg

Other parts of notmuch (e.g. notmuch show) expect each thread to
contain at least one top level message, and crash if this expectation
is not met.

diff --git a/lib/thread.cc b/lib/thread.cc
index 3561b27f743976d2c2d1918d33fc2a8d33469c74..dbac002fd7130c4c7559dcf96fbb9b90bdab2487 100644 (file)
--- a/lib/thread.cc
+++ b/lib/thread.cc
@@ -397,7 +397,13 @@ _resolve_thread_relationships (notmuch_thread_t *thread)
     for (node = thread->message_list->head; node; node = node->next) {
        message = node->message;
        in_reply_to = _notmuch_message_get_in_reply_to (message);
-       if (in_reply_to && strlen (in_reply_to) &&
+       /*
+        * if we reach the end of the list without finding a top-level
+        * message, that means the thread is a cycle (or set of
+        * cycles) and any message can be considered top-level
+        */
+       if ((thread->toplevel_list->head || node->next) &&
+            in_reply_to && strlen (in_reply_to) &&
            g_hash_table_lookup_extended (thread->message_hash,
                                          in_reply_to, NULL,
                                          (void **) &parent))

diff --git a/test/T050-new.sh b/test/T050-new.sh
index b98549781d5302ec04d204fde1d2c24d36017ec7..f3bfe7b159ab042d163dd1f22447948de4aafb14 100755 (executable)
--- a/test/T050-new.sh
+++ b/test/T050-new.sh
@@ -356,7 +356,6 @@ test_expect_equal_file EXPECTED OUTPUT
 
 add_email_corpus broken
 test_begin_subtest "reference loop does not crash"
-test_subtest_known_broken
 test_expect_code 0 "notmuch show --format=json id:mid-loop-12@example.org id:mid-loop-21@example.org > OUTPUT"
 
 test_done