use EMPTY_STRING in _parent_via_in_reply_to

[notmuch] / lib / thread.cc

diff --git a/lib/thread.cc b/lib/thread.cc
index 1632da4cd0f4f9398e774b8157004e89914485d9..4711319d2cf67618edfe7c74b78a0c940bbf9784 100644 (file)
--- a/lib/thread.cc
+++ b/lib/thread.cc
@@ -24,6 +24,12 @@
 #include <gmime/gmime.h>
 #include <glib.h> /* GHashTable */
 
+#ifdef DEBUG_THREADING
+#define THREAD_DEBUG(format, ...) fprintf(stderr, format " (%s).\n", ##__VA_ARGS__, __location__)
+#else
+#define THREAD_DEBUG(format, ...) do {} while (0) /* ignored */
+#endif
+
 #define EMPTY_STRING(s) ((s)[0] == '\0')
 
 struct _notmuch_thread {
@@ -160,6 +166,9 @@ _resolve_thread_authors_string (notmuch_thread_t *thread)
     thread->authors_array = NULL;
     g_ptr_array_free (thread->matched_authors_array, true);
     thread->matched_authors_array = NULL;
+
+    if (!thread->authors)
+       thread->authors = talloc_strdup(thread, "");
 }
 
 /* clean up the ugly "Lastname, Firstname" format that some mail systems
@@ -384,25 +393,62 @@ _thread_add_matched_message (notmuch_thread_t *thread,
     _thread_add_matched_author (thread, _notmuch_message_get_author (hashed_message));
 }
 
+static bool
+_parent_via_in_reply_to (notmuch_thread_t *thread, notmuch_message_t *message) {
+    notmuch_message_t *parent;
+    const char *in_reply_to;
+
+    in_reply_to = _notmuch_message_get_in_reply_to (message);
+    THREAD_DEBUG("checking message = %s in_reply_to=%s\n",
+                notmuch_message_get_message_id (message), in_reply_to);
+
+    if (in_reply_to && (! EMPTY_STRING(in_reply_to)) &&
+       g_hash_table_lookup_extended (thread->message_hash,
+                                     in_reply_to, NULL,
+                                     (void **) &parent)) {
+       _notmuch_message_add_reply (parent, message);
+       return true;
+    } else {
+       return false;
+    }
+}
+
 static void
 _resolve_thread_relationships (notmuch_thread_t *thread)
 {
-    notmuch_message_node_t *node;
-    notmuch_message_t *message, *parent;
-    const char *in_reply_to;
+    notmuch_message_node_t *node, *first_node;
+    notmuch_message_t *message;
 
-    for (node = thread->message_list->head; node; node = node->next) {
+    first_node = thread->message_list->head;
+    if (! first_node)
+       return;
+
+    for (node = first_node->next; 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) &&
-           g_hash_table_lookup_extended (thread->message_hash,
-                                         in_reply_to, NULL,
-                                         (void **) &parent))
-           _notmuch_message_add_reply (parent, message);
-       else
+       if (! _parent_via_in_reply_to (thread, message))
            _notmuch_message_list_add_message (thread->toplevel_list, message);
     }
 
+    /*
+     * 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.  Choose the oldest
+     * message, which happens to be first in our list.
+     */
+    if (first_node) {
+       message = first_node->message;
+        if (_notmuch_message_list_empty(thread->toplevel_list) ||
+           ! _parent_via_in_reply_to (thread, message)) {
+           _notmuch_message_list_add_message (thread->toplevel_list, message);
+       }
+    }
+
+    /* XXX this could be made conditional on messages being inserted
+     * (out of order) in later passes
+     */
+    thread->toplevel_list = _notmuch_message_sort_subtrees (thread, thread->toplevel_list);
+
+
     /* XXX: After scanning through the entire list looking for parents
      * via "In-Reply-To", we should do a second pass that looks at the
      * list of messages IDs in the "References" header instead. (And