# 
# patch "ChangeLog"
#  from [ed4b3b3c1194479a7c7b4767a0f32f3b5ffb5971]
#    to [0f79b1bab4944e0d171410d02195b6e0aa344b39]
# 
# patch "database.cc"
#  from [83c0e4fe4b672da030bc50966c118ac0c2c98017]
#    to [4a6486b38a02fec9b281ae4a665f209bb9f3440e]
# 
========================================================================
--- ChangeLog	ed4b3b3c1194479a7c7b4767a0f32f3b5ffb5971
+++ ChangeLog	0f79b1bab4944e0d171410d02195b6e0aa344b39
@@ -1,5 +1,12 @@
 2005-09-20  Matt Johnston  <address@hidden>
 
+	* database.cc (space_usage): workaround the issue that in sqlite
+	3.2.6, SUM({empty set}) returns NULL. (this is part of the sql spec,
+	see http://www.sqlite.org/cvstrac/tktview?tn=1413 and the comment for
+	SUM() in sqlite docs).
+
+2005-09-20  Matt Johnston  <address@hidden>
+
 	* ui.cc, ui.hh, sanity.hh: replace ui.user_locale with
 	get_user_locale(), so that we can guarantee that it will be
 	initialised when the global_sanity object (and probably other things)
========================================================================
--- database.cc	83c0e4fe4b672da030bc50966c118ac0c2c98017
+++ database.cc	4a6486b38a02fec9b281ae4a665f209bb9f3440e
@@ -757,7 +757,9 @@
 database::space_usage(string const & table, string const & concatenated_columns)
 {
   results res;
-  string query = "SELECT SUM(LENGTH(" + concatenated_columns + ")) FROM " + table;
+  // COALESCE is required since SUM({empty set}) is NULL.
+  // the sqlite docs for SUM suggest this as a workaround
+  string query = "SELECT COALESCE(SUM(LENGTH(" + concatenated_columns + ")), 0) FROM " + table;
   fetch(res, one_col, one_row, query.c_str());
   return lexical_cast<unsigned long>(res[0][0]);
 }