thread.cc: Avoid empty thread names if possible.

[notmuch.git] / lib / thread.cc

diff --git a/lib/thread.cc b/lib/thread.cc
index 79c3e9bb5d463e84b3466c76ab307dddf013c19e..45425056034fca555d8c679d670800872813ba13 100644 (file)
--- a/lib/thread.cc
+++ b/lib/thread.cc
@@ -24,6 +24,8 @@
 #include <gmime/gmime.h>
 #include <glib.h> /* GHashTable */
 
+#define EMPTY_STRING(s) ((s)[0] == '\0')
+
 struct visible _notmuch_thread {
     notmuch_database_t *notmuch;
     char *thread_id;
@@ -332,10 +334,12 @@ _thread_set_subject_from_message (notmuch_thread_t *thread,
        cleaned_subject = talloc_strdup (thread, subject);
     }
 
-    if (thread->subject)
-       talloc_free (thread->subject);
+    if (! EMPTY_STRING(cleaned_subject)) {
+       if (thread->subject)
+           talloc_free (thread->subject);
 
-    thread->subject = talloc_strdup (thread, cleaned_subject);
+       thread->subject = talloc_strdup (thread, cleaned_subject);
+    }
 }
 
 /* Add a message to this thread which is known to match the original
@@ -349,8 +353,10 @@ _thread_add_matched_message (notmuch_thread_t *thread,
 {
     time_t date;
     notmuch_message_t *hashed_message;
+    const char *cur_subject;
 
     date = notmuch_message_get_date (message);
+    cur_subject = notmuch_thread_get_subject(thread);
 
     if (date < thread->oldest || ! thread->matched_messages) {
        thread->oldest = date;
@@ -360,7 +366,7 @@ _thread_add_matched_message (notmuch_thread_t *thread,
 
     if (date > thread->newest || ! thread->matched_messages) {
        thread->newest = date;
-       if (sort != NOTMUCH_SORT_OLDEST_FIRST)
+       if (sort != NOTMUCH_SORT_OLDEST_FIRST || EMPTY_STRING(cur_subject))
            _thread_set_subject_from_message (thread, message);
     }