Ticket #855: xapian-trac855-candidate-fix.patch

xapian-core/backends/glass/glass_postlist.cc

@@ -701 +701 @@
           this_db(keep_reference ? this_db_ : nullptr),
           have_started(false),
           is_at_end(false),
+          all_docs(term_.empty()),
           cursor(this_db_->postlist_table.cursor_get())
 {
     LOGCALL_CTOR(DB, "GlassPostList", this_db_.get() | term_ | keep_reference);
@@ -714 +715 @@
           this_db(this_db_),
           have_started(false),
           is_at_end(false),
+          all_docs(term_.empty()),
           cursor(cursor_)
 {
     LOGCALL_CTOR(DB, "GlassPostList", this_db_.get() | term_ | cursor_);
@@ -814 +816 @@
     const char * keypos = cursor->current_key.data();
     const char * keyend = keypos + cursor->current_key.size();
     // Check we're still in same postlist
-    if (!check_term_in_key_lite(&keypos, keyend, term)) {
+    string_view kterm = all_docs ? string_view() : term;
+    if (!check_term_in_key_lite(&keypos, keyend, kterm)) {
         is_at_end = true;
         throw Xapian::DatabaseCorruptError("Unexpected end of posting list for '" +
                                      term + "'");
@@ -900 +903 @@
 GlassPostList::move_to_chunk_containing(Xapian::docid desired_did)
 {
     LOGCALL_VOID(DB, "GlassPostList::move_to_chunk_containing", desired_did);
-    (void)cursor->find_entry(GlassPostListTable::make_key(term, desired_did));
+    string_view kterm = all_docs ? string_view() : term;
+    (void)cursor->find_entry(GlassPostListTable::make_key(kterm, desired_did));
     Assert(!cursor->after_end());
 
     const char * keypos = cursor->current_key.data();
     const char * keyend = keypos + cursor->current_key.size();
     // Check we're still in same postlist
-    if (!check_term_in_key_lite(&keypos, keyend, term)) {
+    if (!check_term_in_key_lite(&keypos, keyend, kterm)) {
         // This should only happen if the postlist doesn't exist at all.
         is_at_end = true;
         is_last_chunk = true;

xapian-core/backends/glass/glass_postlist.h

@@ -69 +69 @@
     /// Whether we've run off the end of the list yet.
     bool is_at_end;
 
+    /** Are we iterating all docs?
+     *
+     *  This is true for the GlassPostList for the doc lengths.
+     *
+     *  We also use it for a term which indexes all the documents if we don't
+     *  need wdfs.  We call set_term() so can't just use the term name to
+     *  build keys, etc after construction.
+     */
+    bool all_docs = false;
+
     /// Cursor pointing to current chunk of postlist.
     std::unique_ptr<GlassCursor> cursor;