ETableSortInfo: Rework API to avoid exposing ETableSortColumn.

Replace ETableSortColumn with separate ETableColumnSpecification and
GtkSortType parameters in the "get_nth" and "set_nth" functions.

Makes some other parts of the code simpler since it no longer has to
translate a column number to a column specification.

10 files changed, 549 insertions, 396 deletions

diff --git a/doc/reference/evolution-util/evolution-util-sections.txt b/doc/reference/evolution-util/evolution-util-sections.txt
index c303f74e03..a5d2330114 100644
--- a/doc/reference/evolution-util/evolution-util-sections.txt
+++ b/doc/reference/evolution-util/evolution-util-sections.txt
@@ -3874,7 +3874,6 @@ e_table_sort_info_get_can_group
 e_table_sort_info_set_can_group
 e_table_sort_info_grouping_get_count
 e_table_sort_info_grouping_truncate
-ETableSortColumn
 e_table_sort_info_grouping_get_nth
 e_table_sort_info_grouping_set_nth
 e_table_sort_info_sorting_get_count
diff --git a/e-util/e-table-config.c b/e-util/e-table-config.c
index cf0c4e6511..8f339b5c1d 100644
--- a/e-util/e-table-config.c
+++ b/e-util/e-table-config.c
@@ -238,10 +238,10 @@ configure_combo_box_set_active (GtkComboBox *combo_box,
 }
 
 static ETableColumnSpecification *
-find_column_in_spec (ETableSpecification *spec,
-                     gint model_col)
+find_column_spec_by_name (ETableSpecification *spec,
+                          const gchar *s)
 {
-	ETableColumnSpecification *column = NULL;
+	ETableColumnSpecification *column;
 	GPtrArray *array;
 	guint ii;
 
@@ -255,7 +255,7 @@ find_column_in_spec (ETableSpecification *spec,
 		if (candidate->disabled)
 			continue;
 
-		if (candidate->model_col == model_col) {
+		if (g_ascii_strcasecmp (candidate->title, s) == 0) {
 			column = candidate;
 			break;
 		}
@@ -266,35 +266,6 @@ find_column_in_spec (ETableSpecification *spec,
 	return column;
 }
 
-static gint
-find_model_column_by_name (ETableSpecification *spec,
-                           const gchar *s)
-{
-	GPtrArray *array;
-	gint model_col = -1;
-	guint ii;
-
-	array = e_table_specification_ref_columns (spec);
-
-	for (ii = 0; ii < array->len; ii++) {
-		ETableColumnSpecification *candidate;
-
-		candidate = g_ptr_array_index (array, ii);
-
-		if (candidate->disabled)
-			continue;
-
-		if (g_ascii_strcasecmp (candidate->title, s) == 0) {
-			model_col = candidate->model_col;
-			break;
-		}
-	}
-
-	g_ptr_array_unref (array);
-
-	return model_col;
-}
-
 static void
 update_sort_and_group_config_dialog (ETableConfig *config,
                                      gboolean is_sort)
@@ -329,20 +300,20 @@ update_sort_and_group_config_dialog (ETableConfig *config,
 			widgets[i].changed_id);
 
 		if (i < count) {
-			GtkToggleButton *a, *d;
-			ETableSortColumn col =
-				is_sort
-				? e_table_sort_info_sorting_get_nth (
-					config->temp_state->sort_info,
-					i)
-				:  e_table_sort_info_grouping_get_nth (
-					config->temp_state->sort_info,
-					i);
-
-			ETableColumnSpecification *column =
-				find_column_in_spec (config->source_spec, col.column);
-
-			if (!column) {
+			GtkWidget *toggle_button;
+			ETableColumnSpecification *column;
+			GtkSortType sort_type;
+
+			if (is_sort)
+				column = e_table_sort_info_sorting_get_nth (
+					config->temp_state->sort_info, i,
+					&sort_type);
+			else
+				column = e_table_sort_info_grouping_get_nth (
+					config->temp_state->sort_info, i,
+					&sort_type);
+
+			if (column == NULL) {
 				/*
 				 * This is a bug in the programmer
 				 * stuff, but by the time we arrive
@@ -357,12 +328,15 @@ update_sort_and_group_config_dialog (ETableConfig *config,
 			/*
 			 * Update radio buttons
 			 */
-			a = GTK_TOGGLE_BUTTON (
-				widgets[i].radio_ascending);
-			d = GTK_TOGGLE_BUTTON (
-				widgets[i].radio_descending);
 
-			gtk_toggle_button_set_active (col.ascending ? a : d, 1);
+			if (sort_type == GTK_SORT_ASCENDING)
+				toggle_button = widgets[i].radio_ascending;
+			else
+				toggle_button = widgets[i].radio_descending;
+
+			gtk_toggle_button_set_active (
+				GTK_TOGGLE_BUTTON (toggle_button), TRUE);
+
 		} else {
 			GtkToggleButton *t;
 
@@ -396,19 +370,23 @@ update_sort_and_group_config_dialog (ETableConfig *config,
 static void
 config_sort_info_update (ETableConfig *config)
 {
-	ETableSortInfo *info = config->state->sort_info;
+	ETableSortInfo *sort_info;
 	GString *res;
 	gint count, i;
 
-	count = e_table_sort_info_sorting_get_count (info);
+	sort_info = config->state->sort_info;
+
+	count = e_table_sort_info_sorting_get_count (sort_info);
 	res = g_string_new ("");
 
 	for (i = 0; i < count; i++) {
-		ETableSortColumn col = e_table_sort_info_sorting_get_nth (info, i);
 		ETableColumnSpecification *column;
+		GtkSortType sort_type;
+
+		column = e_table_sort_info_sorting_get_nth (
+			sort_info, i, &sort_type);
 
-		column = find_column_in_spec (config->source_spec, col.column);
-		if (!column) {
+		if (column == NULL) {
 			g_warning ("Could not find column model in specification");
 			continue;
 		}
@@ -417,7 +395,7 @@ config_sort_info_update (ETableConfig *config)
 		g_string_append_c (res, ' ');
 		g_string_append (
 			res,
-			col.ascending ?
+			(sort_type == GTK_SORT_ASCENDING) ?
 			_("(Ascending)") : _("(Descending)"));
 
 		if ((i + 1) != count)
@@ -435,22 +413,26 @@ config_sort_info_update (ETableConfig *config)
 static void
 config_group_info_update (ETableConfig *config)
 {
-	ETableSortInfo *info = config->state->sort_info;
+	ETableSortInfo *sort_info;
 	GString *res;
 	gint count, i;
 
-	if (!e_table_sort_info_get_can_group (info))
+	sort_info = config->state->sort_info;
+
+	if (!e_table_sort_info_get_can_group (sort_info))
 		return;
 
-	count = e_table_sort_info_grouping_get_count (info);
+	count = e_table_sort_info_grouping_get_count (sort_info);
 	res = g_string_new ("");
 
 	for (i = 0; i < count; i++) {
-		ETableSortColumn col = e_table_sort_info_grouping_get_nth (info, i);
 		ETableColumnSpecification *column;
+		GtkSortType sort_type;
+
+		column = e_table_sort_info_grouping_get_nth (
+			sort_info, i, &sort_type);
 
-		column = find_column_in_spec (config->source_spec, col.column);
-		if (!column) {
+		if (column == NULL) {
 			g_warning ("Could not find model column in specification");
 			continue;
 		}
@@ -459,7 +441,7 @@ config_group_info_update (ETableConfig *config)
 		g_string_append_c (res, ' ');
 		g_string_append (
 			res,
-			col.ascending ?
+			(sort_type == GTK_SORT_ASCENDING) ?
 			_("(Ascending)") : _("(Descending)"));
 
 		if ((i + 1) != count)
@@ -850,18 +832,18 @@ sort_combo_changed (GtkComboBox *combo_box,
 	ETableConfig *config = sort->e_table_config;
 	ETableSortInfo *sort_info = config->temp_state->sort_info;
 	ETableConfigSortWidgets *base = &config->sort[0];
-	GtkToggleButton *toggle_button;
 	gint idx = sort - base;
 	gchar *s;
 
 	s = configure_combo_box_get_active (combo_box);
 
 	if (s != NULL) {
-		ETableSortColumn c;
-		gint col;
+		ETableColumnSpecification *column;
+		GtkToggleButton *toggle_button;
+		GtkSortType sort_type;
 
-		col = find_model_column_by_name (config->source_spec, s);
-		if (col == -1) {
+		column = find_column_spec_by_name (config->source_spec, s);
+		if (column == NULL) {
 			g_warning ("sort: This should not happen (%s)", s);
 			g_free (s);
 			return;
@@ -869,9 +851,13 @@ sort_combo_changed (GtkComboBox *combo_box,
 
 		toggle_button = GTK_TOGGLE_BUTTON (
 			config->sort[idx].radio_ascending);
-		c.ascending = gtk_toggle_button_get_active (toggle_button);
-		c.column = col;
-		e_table_sort_info_sorting_set_nth (sort_info, idx, c);
+		if (gtk_toggle_button_get_active (toggle_button))
+			sort_type = GTK_SORT_ASCENDING;
+		else
+			sort_type = GTK_SORT_DESCENDING;
+
+		e_table_sort_info_sorting_set_nth (
+			sort_info, idx, column, sort_type);
 
 		update_sort_and_group_config_dialog (config, TRUE);
 	}  else {
@@ -883,18 +869,23 @@ sort_combo_changed (GtkComboBox *combo_box,
 }
 
 static void
-sort_ascending_toggled (GtkToggleButton *t,
+sort_ascending_toggled (GtkToggleButton *toggle_button,
                         ETableConfigSortWidgets *sort)
 {
 	ETableConfig *config = sort->e_table_config;
 	ETableSortInfo *si = config->temp_state->sort_info;
 	ETableConfigSortWidgets *base = &config->sort[0];
+	ETableColumnSpecification *column;
+	GtkSortType sort_type;
 	gint idx = sort - base;
-	ETableSortColumn c;
 
-	c = e_table_sort_info_sorting_get_nth (si, idx);
-	c.ascending = gtk_toggle_button_get_active (t);
-	e_table_sort_info_sorting_set_nth (si, idx, c);
+	if (gtk_toggle_button_get_active (toggle_button))
+		sort_type = GTK_SORT_ASCENDING;
+	else
+		sort_type = GTK_SORT_DESCENDING;
+
+	column = e_table_sort_info_sorting_get_nth (si, idx, NULL);
+	e_table_sort_info_sorting_set_nth (si, idx, column, sort_type);
 }
 
 static void
@@ -982,12 +973,12 @@ group_combo_changed (GtkComboBox *combo_box,
 	s = configure_combo_box_get_active (combo_box);
 
 	if (s != NULL) {
+		ETableColumnSpecification *column;
 		GtkToggleButton *toggle_button;
-		ETableSortColumn c;
-		gint col;
+		GtkSortType sort_type;
 
-		col = find_model_column_by_name (config->source_spec, s);
-		if (col == -1) {
+		column = find_column_spec_by_name (config->source_spec, s);
+		if (column == NULL) {
 			g_warning ("grouping: this should not happen, %s", s);
 			g_free (s);
 			return;
@@ -995,9 +986,13 @@ group_combo_changed (GtkComboBox *combo_box,
 
 		toggle_button = GTK_TOGGLE_BUTTON (
 			config->group[idx].radio_ascending);
-		c.ascending = gtk_toggle_button_get_active (toggle_button);
-		c.column = col;
-		e_table_sort_info_grouping_set_nth (sort_info, idx, c);
+		if (gtk_toggle_button_get_active (toggle_button))
+			sort_type = GTK_SORT_ASCENDING;
+		else
+			sort_type = GTK_SORT_DESCENDING;
+
+		e_table_sort_info_grouping_set_nth (
+			sort_info, idx, column, sort_type);
 
 		update_sort_and_group_config_dialog (config, FALSE);
 	}  else {
@@ -1009,18 +1004,23 @@ group_combo_changed (GtkComboBox *combo_box,
 }
 
 static void
-group_ascending_toggled (GtkToggleButton *t,
+group_ascending_toggled (GtkToggleButton *toggle_button,
                          ETableConfigSortWidgets *group)
 {
 	ETableConfig *config = group->e_table_config;
 	ETableSortInfo *si = config->temp_state->sort_info;
 	ETableConfigSortWidgets *base = &config->group[0];
+	ETableColumnSpecification *column;
+	GtkSortType sort_type;
 	gint idx = group - base;
-	ETableSortColumn c;
 
-	c = e_table_sort_info_grouping_get_nth (si, idx);
-	c.ascending = gtk_toggle_button_get_active (t);
-	e_table_sort_info_grouping_set_nth (si, idx, c);
+	if (gtk_toggle_button_get_active (toggle_button))
+		sort_type = GTK_SORT_ASCENDING;
+	else
+		sort_type = GTK_SORT_DESCENDING;
+
+	column = e_table_sort_info_grouping_get_nth (si, idx, NULL);
+	e_table_sort_info_grouping_set_nth (si, idx, column, sort_type);
 }
 
 static void
diff --git a/e-util/e-table-group-container.c b/e-util/e-table-group-container.c
index 68239b123f..d828ddec3e 100644
--- a/e-util/e-table-group-container.c
+++ b/e-util/e-table-group-container.c
@@ -150,12 +150,15 @@ e_table_group_container_construct (GnomeCanvasGroup *parent,
                                    ETableSortInfo *sort_info,
                                    gint n)
 {
+	ETableColumnSpecification *spec;
 	ETableCol *col;
-	ETableSortColumn column = e_table_sort_info_grouping_get_nth (sort_info, n);
 	GtkWidget *widget;
 	GtkStyle *style;
+	GtkSortType sort_type;
+
+	spec = e_table_sort_info_grouping_get_nth (sort_info, n, &sort_type);
+	col = e_table_header_get_column_by_spec (full_header, spec);
 
-	col = e_table_header_get_column_by_col_idx (full_header, column.column);
 	if (col == NULL) {
 		gint last = e_table_header_count (full_header) - 1;
 		col = e_table_header_get_column (full_header, last);
@@ -166,7 +169,7 @@ e_table_group_container_construct (GnomeCanvasGroup *parent,
 	etgc->ecol = g_object_ref (col);
 	etgc->sort_info = g_object_ref (sort_info);
 	etgc->n = n;
-	etgc->ascending = column.ascending;
+	etgc->ascending = (sort_type == GTK_SORT_ASCENDING);
 
 	widget = GTK_WIDGET (GNOME_CANVAS_ITEM (etgc)->canvas);
 	style = gtk_widget_get_style (widget);
diff --git a/e-util/e-table-header-item.c b/e-util/e-table-header-item.c
index 8dcdf06c19..ea7145c844 100644
--- a/e-util/e-table-header-item.c
+++ b/e-util/e-table-header-item.c
@@ -997,32 +997,34 @@ ethi_draw (GnomeCanvasItem *item,
 
 		length = e_table_sort_info_grouping_get_count (ethi->sort_info);
 		for (i = 0; i < length; i++) {
-			ETableSortColumn column;
+			ETableColumnSpecification *spec;
+			GtkSortType sort_type;
 
-			column = e_table_sort_info_grouping_get_nth (
-				ethi->sort_info, i);
+			spec = e_table_sort_info_grouping_get_nth (
+				ethi->sort_info, i, &sort_type);
 
 			g_hash_table_insert (
 				arrows,
-				GINT_TO_POINTER ((gint) column.column),
+				GINT_TO_POINTER (spec->model_col),
 				GINT_TO_POINTER (
-					column.ascending ?
+					(sort_type == GTK_SORT_ASCENDING) ?
 					E_TABLE_COL_ARROW_DOWN :
 					E_TABLE_COL_ARROW_UP));
 		}
 
 		length = e_table_sort_info_sorting_get_count (ethi->sort_info);
 		for (i = 0; i < length; i++) {
-			ETableSortColumn column;
+			ETableColumnSpecification *spec;
+			GtkSortType sort_type;
 
-			column = e_table_sort_info_sorting_get_nth (
-				ethi->sort_info, i);
+			spec = e_table_sort_info_sorting_get_nth (
+				ethi->sort_info, i, &sort_type);
 
 			g_hash_table_insert (
 				arrows,
-				GINT_TO_POINTER ((gint) column.column),
+				GINT_TO_POINTER (spec->model_col),
 				GINT_TO_POINTER (
-					column.ascending ?
+					(sort_type == GTK_SORT_ASCENDING) ?
 					E_TABLE_COL_ARROW_DOWN :
 					E_TABLE_COL_ARROW_UP));
 		}
@@ -1241,29 +1243,35 @@ ethi_start_drag (ETableHeaderItem *ethi,
 		gint length = e_table_sort_info_grouping_get_count (ethi->sort_info);
 		gint i;
 		for (i = 0; i < length; i++) {
-			ETableSortColumn column =
-				e_table_sort_info_grouping_get_nth (
-					ethi->sort_info, i);
+			ETableColumnSpecification *spec;
+			GtkSortType sort_type;
+
 			group_indent++;
+
+			spec = e_table_sort_info_grouping_get_nth (
+				ethi->sort_info, i, &sort_type);
+
 			g_hash_table_insert (
 				arrows,
-				GINT_TO_POINTER ((gint) column.column),
+				GINT_TO_POINTER (spec->model_col),
 				GINT_TO_POINTER (
-					column.ascending ?
+					(sort_type == GTK_SORT_ASCENDING) ?
 					E_TABLE_COL_ARROW_DOWN :
 					E_TABLE_COL_ARROW_UP));
 		}
 		length = e_table_sort_info_sorting_get_count (ethi->sort_info);
 		for (i = 0; i < length; i++) {
-			ETableSortColumn column =
-				e_table_sort_info_sorting_get_nth (
-					ethi->sort_info, i);
+			ETableColumnSpecification *spec;
+			GtkSortType sort_type;
+
+			spec = e_table_sort_info_sorting_get_nth (
+				ethi->sort_info, i, &sort_type);
 
 			g_hash_table_insert (
 				arrows,
-				GINT_TO_POINTER ((gint) column.column),
+				GINT_TO_POINTER (spec->model_col),
 				GINT_TO_POINTER (
-					column.ascending ?
+					(sort_type == GTK_SORT_ASCENDING) ?
 					E_TABLE_COL_ARROW_DOWN :
 					E_TABLE_COL_ARROW_UP));
 		}
@@ -1304,8 +1312,8 @@ static void
 ethi_popup_sort_ascending (GtkWidget *widget,
                            EthiHeaderInfo *info)
 {
+	ETableColumnSpecification *col_spec = NULL;
 	ETableCol *col;
-	gint model_col = -1;
 	gint length;
 	gint i;
 	gint found = FALSE;
@@ -1313,46 +1321,49 @@ ethi_popup_sort_ascending (GtkWidget *widget,
 
 	col = e_table_header_get_column (ethi->eth, info->col);
 	if (col->spec->sortable)
-		model_col = col->spec->model_col;
+		col_spec = col->spec;
 
 	length = e_table_sort_info_grouping_get_count (ethi->sort_info);
 	for (i = 0; i < length; i++) {
-		ETableSortColumn column = e_table_sort_info_grouping_get_nth (
-			ethi->sort_info, i);
+		ETableColumnSpecification *spec;
+
+		spec = e_table_sort_info_grouping_get_nth (
+			ethi->sort_info, i, NULL);
 
-		if (model_col == column.column) {
-			column.ascending = 1;
+		if (e_table_column_specification_equal (col_spec, spec)) {
 			e_table_sort_info_grouping_set_nth (
-				ethi->sort_info, i, column);
-			found = 1;
-			break;
+				ethi->sort_info, i, spec,
+				GTK_SORT_ASCENDING);
+			return;
 		}
 	}
-	if (!found) {
-		length = e_table_sort_info_sorting_get_count (
-			ethi->sort_info);
-		for (i = 0; i < length; i++) {
-			ETableSortColumn column =
-				e_table_sort_info_sorting_get_nth (
-					ethi->sort_info, i);
-			if (model_col == column.column || model_col == -1) {
-				column.ascending = 1;
-				e_table_sort_info_sorting_set_nth (
-					ethi->sort_info, i, column);
-				found = 1;
-				if (model_col != -1)
-					break;
-			}
+
+	length = e_table_sort_info_sorting_get_count (ethi->sort_info);
+	for (i = 0; i < length; i++) {
+		ETableColumnSpecification *spec;
+
+		spec = e_table_sort_info_sorting_get_nth (
+			ethi->sort_info, i, NULL);
+
+		if (col_spec == NULL ||
+		    e_table_column_specification_equal (col_spec, spec)) {
+			e_table_sort_info_sorting_set_nth (
+				ethi->sort_info, i, spec,
+				GTK_SORT_ASCENDING);
+			found = TRUE;
+			if (col_spec != NULL)
+				return;
 		}
 	}
+
 	if (!found) {
-		ETableSortColumn column;
-		column.column = model_col;
-		column.ascending =  1;
 		length = e_table_sort_info_sorting_get_count (ethi->sort_info);
 		if (length == 0)
 			length++;
-		e_table_sort_info_sorting_set_nth (ethi->sort_info, length - 1, column);
+
+		e_table_sort_info_sorting_set_nth (
+			ethi->sort_info, length - 1,
+			col_spec, GTK_SORT_ASCENDING);
 	}
 }
 
@@ -1360,8 +1371,8 @@ static void
 ethi_popup_sort_descending (GtkWidget *widget,
                             EthiHeaderInfo *info)
 {
+	ETableColumnSpecification *col_spec = NULL;
 	ETableCol *col;
-	gint model_col=-1;
 	gint length;
 	gint i;
 	gint found = FALSE;
@@ -1369,46 +1380,50 @@ ethi_popup_sort_descending (GtkWidget *widget,
 
 	col = e_table_header_get_column (ethi->eth, info->col);
 	if (col->spec->sortable)
-		model_col = col->spec->model_col;
+		col_spec = col->spec;
 
 	length = e_table_sort_info_grouping_get_count (ethi->sort_info);
 	for (i = 0; i < length; i++) {
-		ETableSortColumn column = e_table_sort_info_grouping_get_nth (
-			ethi->sort_info, i);
-		if (model_col == column.column) {
-			column.ascending = 0;
+		ETableColumnSpecification *spec;
+		GtkSortType sort_type;
+
+		spec = e_table_sort_info_grouping_get_nth (
+			ethi->sort_info, i, &sort_type);
+
+		if (e_table_column_specification_equal (col_spec, spec)) {
 			e_table_sort_info_grouping_set_nth (
-				ethi->sort_info, i, column);
-			found = 1;
-			break;
+				ethi->sort_info, i, spec,
+				GTK_SORT_DESCENDING);
+			return;
 		}
 	}
-	if (!found) {
-		length = e_table_sort_info_sorting_get_count (ethi->sort_info);
-		for (i = 0; i < length; i++) {
-			ETableSortColumn column =
-				e_table_sort_info_sorting_get_nth (
-					ethi->sort_info, i);
-
-			if (model_col == column.column || model_col == -1) {
-				column.ascending = 0;
-				e_table_sort_info_sorting_set_nth (
-					ethi->sort_info, i, column);
-				found = 1;
-				if (model_col != -1)
-					break;
-			}
+
+	length = e_table_sort_info_sorting_get_count (ethi->sort_info);
+	for (i = 0; i < length; i++) {
+		ETableColumnSpecification *spec;
+
+		spec = e_table_sort_info_sorting_get_nth (
+			ethi->sort_info, i, NULL);
+
+		if (col_spec == NULL ||
+		    e_table_column_specification_equal (col_spec, spec)) {
+			e_table_sort_info_sorting_set_nth (
+				ethi->sort_info, i, spec,
+				GTK_SORT_DESCENDING);
+			found = TRUE;
+			if (col_spec != NULL)
+				break;
 		}
 	}
+
 	if (!found) {
-		ETableSortColumn column;
-		column.column = model_col;
-		column.ascending = 0;
 		length = e_table_sort_info_sorting_get_count (ethi->sort_info);
 		if (length == 0)
 			length++;
+
 		e_table_sort_info_sorting_set_nth (
-			ethi->sort_info, length - 1, column);
+			ethi->sort_info, length - 1,
+			col_spec, GTK_SORT_DESCENDING);
 	}
 }
 
@@ -1427,17 +1442,13 @@ ethi_popup_group_field (GtkWidget *widget,
                         EthiHeaderInfo *info)
 {
 	ETableCol *col;
-	gint model_col;
-	ETableHeaderItem *ethi = info->ethi;
-	ETableSortColumn column;
 
-	col = e_table_header_get_column (ethi->eth, info->col);
-	model_col = col->spec->model_col;
+	col = e_table_header_get_column (info->ethi->eth, info->col);
 
-	column.column = model_col;
-	column.ascending = 1;
-	e_table_sort_info_grouping_set_nth (ethi->sort_info, 0, column);
-	e_table_sort_info_grouping_truncate (ethi->sort_info, 1);
+	e_table_sort_info_grouping_set_nth (
+		info->ethi->sort_info, 0,
+		col->spec, GTK_SORT_ASCENDING);
+	e_table_sort_info_grouping_truncate (info->ethi->sort_info, 1);
 }
 
 static void
@@ -1632,10 +1643,11 @@ sort_by_id (GtkWidget *menu_item,
 
 	if (!clearfirst && ecol &&
 		e_table_sort_info_sorting_get_count (ethi->sort_info) == 1) {
-		ETableSortColumn column;
+		ETableColumnSpecification *spec;
 
-		column = e_table_sort_info_sorting_get_nth (ethi->sort_info, 0);
-		clearfirst = ecol->spec->sortable && ecol->spec->model_col != column.column;
+		spec = e_table_sort_info_sorting_get_nth (
+			ethi->sort_info, 0, NULL);
+		clearfirst = ecol->spec->sortable && ecol->spec != spec;
 	}
 
 	if (clearfirst)
@@ -1659,7 +1671,6 @@ ethi_header_context_menu (ETableHeaderItem *ethi,
 	GtkMenu *popup;
 	gint ncol, sort_count, sort_col;
 	GtkWidget *menu_item, *sub_menu;
-	ETableSortColumn column;
 	gboolean ascending = TRUE;
 	gdouble event_x_win = 0;
 	gdouble event_y_win = 0;
@@ -1695,9 +1706,14 @@ ethi_header_context_menu (ETableHeaderItem *ethi,
 	if (sort_count > 1 || sort_count < 1)
 		sort_col = -1; /* Custom sorting */
 	else {
-		column = e_table_sort_info_sorting_get_nth (ethi->sort_info, 0);
-		sort_col = column.column;
-		ascending = column.ascending;
+		ETableColumnSpecification *spec;
+		GtkSortType sort_type;
+
+		spec = e_table_sort_info_sorting_get_nth (
+			ethi->sort_info, 0, &sort_type);
+
+		sort_col = spec->model_col;
+		ascending = (sort_type == GTK_SORT_ASCENDING);
 	}
 
 	/* Custom */
@@ -1773,7 +1789,7 @@ void
 ethi_change_sort_state (ETableHeaderItem *ethi,
                         ETableCol *col)
 {
-	gint model_col = -1;
+	ETableColumnSpecification *col_spec = NULL;
 	gint length;
 	gint i;
 	gboolean found = FALSE;
@@ -1782,22 +1798,28 @@ ethi_change_sort_state (ETableHeaderItem *ethi,
 		return;
 
 	if (col->spec->sortable)
-		model_col = col->spec->model_col;
+		col_spec = col->spec;
 
 	length = e_table_sort_info_grouping_get_count (ethi->sort_info);
 	for (i = 0; i < length; i++) {
-		ETableSortColumn column;
+		ETableColumnSpecification *spec;
+		GtkSortType sort_type;
+
+		spec = e_table_sort_info_grouping_get_nth (
+			ethi->sort_info, i, &sort_type);
 
-		column = e_table_sort_info_grouping_get_nth (
-			ethi->sort_info, i);
+		/* Invert the sort type. */
+		if (sort_type == GTK_SORT_ASCENDING)
+			sort_type = GTK_SORT_DESCENDING;
+		else
+			sort_type = GTK_SORT_ASCENDING;
 
-		if (model_col == column.column || model_col == -1) {
-			gint ascending = column.ascending;
-			ascending = !ascending;
-			column.ascending = ascending;
-			e_table_sort_info_grouping_set_nth (ethi->sort_info, i, column);
+		if (col_spec == NULL ||
+		    e_table_column_specification_equal (col_spec, spec)) {
+			e_table_sort_info_grouping_set_nth (
+				ethi->sort_info, i, spec, sort_type);
 			found = TRUE;
-			if (model_col != -1)
+			if (col_spec != NULL)
 				break;
 		}
 	}
@@ -1805,15 +1827,15 @@ ethi_change_sort_state (ETableHeaderItem *ethi,
 	if (!found) {
 		length = e_table_sort_info_sorting_get_count (ethi->sort_info);
 		for (i = 0; i < length; i++) {
-			ETableSortColumn column;
-
-			column = e_table_sort_info_sorting_get_nth (
-				ethi->sort_info, i);
+			ETableColumnSpecification *spec;
+			GtkSortType sort_type;
 
-			if (model_col == column.column || model_col == -1) {
-				gint ascending = column.ascending;
+			spec = e_table_sort_info_sorting_get_nth (
+				ethi->sort_info, i, &sort_type);
 
-				if (ascending == 0 && model_col != -1) {
+			if (col_spec == NULL ||
+			    e_table_column_specification_equal (col_spec, spec)) {
+				if (sort_type == GTK_SORT_DESCENDING && col_spec != NULL) {
 					/*
 					 * This means the user has clicked twice
 					 * already, lets kill sorting of this column now.
@@ -1823,24 +1845,28 @@ ethi_change_sort_state (ETableHeaderItem *ethi,
 					length--;
 					i--;
 				} else {
-					ascending = !ascending;
-					column.ascending = ascending;
+					/* Invert the sort type. */
+					if (sort_type == GTK_SORT_ASCENDING)
+						sort_type = GTK_SORT_DESCENDING;
+					else
+						sort_type = GTK_SORT_ASCENDING;
+
 					e_table_sort_info_sorting_set_nth (
-						ethi->sort_info, i, column);
+						ethi->sort_info, i, spec, sort_type);
 				}
 				found = TRUE;
-				if (model_col != -1)
+				if (col_spec != NULL)
 					break;
 			}
 		}
 	}
 
-	if (!found && model_col != -1) {
-		ETableSortColumn column;
-		column.column = model_col;
-		column.ascending = 1;
+	if (!found && col_spec != NULL) {
 		e_table_sort_info_sorting_truncate (ethi->sort_info, 0);
-		e_table_sort_info_sorting_set_nth (ethi->sort_info, 0, column);
+
+		e_table_sort_info_sorting_set_nth (
+			ethi->sort_info, 0,
+			col_spec, GTK_SORT_ASCENDING);
 	}
 }
 
diff --git a/e-util/e-table-sort-info.c b/e-util/e-table-sort-info.c
index 047e31da6c..28e96f710f 100644
--- a/e-util/e-table-sort-info.c
+++ b/e-util/e-table-sort-info.c
@@ -27,6 +27,8 @@
 	(G_TYPE_INSTANCE_GET_PRIVATE \
 	((obj), E_TYPE_TABLE_SORT_INFO, ETableSortInfoPrivate))
 
+typedef struct _ColumnData ColumnData;
+
 struct _ETableSortInfoPrivate {
 	GWeakRef specification;
 	GArray *groupings;
@@ -34,6 +36,11 @@ struct _ETableSortInfoPrivate {
 	gboolean can_group;
 };
 
+struct _ColumnData {
+	ETableColumnSpecification *column_spec;
+	GtkSortType sort_type;
+};
+
 enum {
 	PROP_0,
 	PROP_SPECIFICATION
@@ -50,6 +57,12 @@ static guint signals[LAST_SIGNAL];
 G_DEFINE_TYPE (ETableSortInfo , e_table_sort_info, G_TYPE_OBJECT)
 
 static void
+column_data_clear (ColumnData *data)
+{
+	g_clear_object (&data->column_spec);
+}
+
+static void
 table_sort_info_set_specification (ETableSortInfo *sort_info,
                                    ETableSpecification *specification)
 {
@@ -173,9 +186,16 @@ e_table_sort_info_init (ETableSortInfo *sort_info)
 	sort_info->priv = E_TABLE_SORT_INFO_GET_PRIVATE (sort_info);
 
 	sort_info->priv->groupings = g_array_new (
-		FALSE, TRUE, sizeof (ETableSortColumn));
+		FALSE, TRUE, sizeof (ColumnData));
+	g_array_set_clear_func (
+		sort_info->priv->groupings,
+		(GDestroyNotify) column_data_clear);
+
 	sort_info->priv->sortings = g_array_new (
-		FALSE, TRUE, sizeof (ETableSortColumn));
+		FALSE, TRUE, sizeof (ColumnData));
+	g_array_set_clear_func (
+		sort_info->priv->sortings,
+		(GDestroyNotify) column_data_clear);
 
 	sort_info->priv->can_group = TRUE;
 }
@@ -279,53 +299,67 @@ e_table_sort_info_grouping_truncate (ETableSortInfo *sort_info,
  * e_table_sort_info_grouping_get_nth:
  * @sort_info: an #ETableSortInfo
  * @n: Item information to fetch.
+ * @out_sort_type: return location for a #GtkSortType value, or %NULL
  *
  * Returns: the description of the @n-th grouping criteria in the @info object.
  */
-ETableSortColumn
+ETableColumnSpecification *
 e_table_sort_info_grouping_get_nth (ETableSortInfo *sort_info,
-                                    guint n)
+                                    guint n,
+                                    GtkSortType *out_sort_type)
 {
-	ETableSortColumn column = { 0, 0 };
+	ETableColumnSpecification *column_spec = NULL;
 	GArray *array;
+	gboolean can_group;
 
-	g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), column);
+	g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), NULL);
 
 	array = sort_info->priv->groupings;
+	can_group = e_table_sort_info_get_can_group (sort_info);
+
+	if (can_group && n < array->len) {
+		ColumnData *column_data;
 
-	if (!e_table_sort_info_get_can_group (sort_info))
-		return column;
+		column_data = &g_array_index (array, ColumnData, n);
 
-	if (n < array->len)
-		column = g_array_index (array, ETableSortColumn, n);
+		if (out_sort_type != NULL)
+			*out_sort_type = column_data->sort_type;
 
-	return column;
+		column_spec = column_data->column_spec;
+	}
+
+	return column_spec;
 }
 
 /**
  * e_table_sort_info_grouping_set_nth:
  * @sort_info: an #ETableSortInfo
  * @n: Item information to fetch.
- * @column: new values for the grouping
+ * @spec: an #ETableColumnSpecification
+ * @sort_type: a #GtkSortType
  *
- * Sets the grouping criteria for index @n to be given by @column
- * (a column number and whether it is ascending or descending).
+ * Sets the grouping criteria for index @n to @spec and @sort_type.
  */
 void
 e_table_sort_info_grouping_set_nth (ETableSortInfo *sort_info,
                                     guint n,
-                                    ETableSortColumn column)
+                                    ETableColumnSpecification *spec,
+                                    GtkSortType sort_type)
 {
-	ETableSortColumn *array_element;
 	GArray *array;
+	ColumnData *column_data;
 
 	g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));
+	g_return_if_fail (E_IS_TABLE_COLUMN_SPECIFICATION (spec));
 
 	array = sort_info->priv->groupings;
 	g_array_set_size (array, MAX (n + 1, array->len));
+	column_data = &g_array_index (array, ColumnData, n);
+
+	column_data_clear (column_data);
 
-	array_element = &g_array_index (array, ETableSortColumn, n);
-	*array_element = column;
+	column_data->column_spec = g_object_ref (spec);
+	column_data->sort_type = sort_type;
 
 	g_signal_emit (sort_info, signals[GROUP_INFO_CHANGED], 0);
 }
@@ -386,50 +420,65 @@ e_table_sort_info_sorting_truncate (ETableSortInfo *sort_info,
  * e_table_sort_info_sorting_get_nth:
  * @sort_info: an #ETableSortInfo
  * @n: Item information to fetch.
+ * @out_sort_type: return location for a #GtkSortType value, or %NULL
  *
  * Returns: the description of the @n-th grouping criteria in the @info object.
  */
-ETableSortColumn
+ETableColumnSpecification *
 e_table_sort_info_sorting_get_nth (ETableSortInfo *sort_info,
-                                   guint n)
+                                   guint n,
+                                   GtkSortType *out_sort_type)
 {
-	ETableSortColumn column = { 0, 0 };
+	ETableColumnSpecification *column_spec = NULL;
 	GArray *array;
 
-	g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), column);
+	g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), NULL);
 
 	array = sort_info->priv->sortings;
 
-	if (n < array->len)
-		column = g_array_index (array, ETableSortColumn, n);
+	if (n < array->len) {
+		ColumnData *column_data;
+
+		column_data = &g_array_index (array, ColumnData, n);
 
-	return column;
+		if (out_sort_type != NULL)
+			*out_sort_type = column_data->sort_type;
+
+		column_spec = column_data->column_spec;
+	}
+
+	return column_spec;
 }
 
 /**
  * e_table_sort_info_sorting_set_nth:
  * @sort_info: an #ETableSortInfo
  * @n: Item information to fetch.
- * @column: new values for the sorting
+ * @spec: an #ETableColumnSpecification
+ * @sort_type: a #GtkSortType
  *
- * Sets the sorting criteria for index @n to be given by @column (a
- * column number and whether it is ascending or descending).
+ * Sets the sorting criteria for index @n to @spec and @sort_type.
  */
 void
 e_table_sort_info_sorting_set_nth (ETableSortInfo *sort_info,
                                    guint n,
-                                   ETableSortColumn column)
+                                   ETableColumnSpecification *spec,
+                                   GtkSortType sort_type)
 {
-	ETableSortColumn *array_element;
 	GArray *array;
+	ColumnData *column_data;
 
 	g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));
+	g_return_if_fail (E_IS_TABLE_COLUMN_SPECIFICATION (spec));
 
 	array = sort_info->priv->sortings;
 	g_array_set_size (array, MAX (n + 1, array->len));
+	column_data = &g_array_index (array, ColumnData, n);
 
-	array_element = &g_array_index (array, ETableSortColumn, n);
-	*array_element = column;
+	column_data_clear (column_data);
+
+	column_data->column_spec = g_object_ref (spec);
+	column_data->sort_type = sort_type;
 
 	g_signal_emit (sort_info, signals[SORT_INFO_CHANGED], 0);
 }
@@ -448,47 +497,71 @@ e_table_sort_info_load_from_node (ETableSortInfo *sort_info,
                                   xmlNode *node,
                                   gdouble state_version)
 {
-	guint i;
+	ETableSpecification *specification;
+	GPtrArray *columns;
 	xmlNode *grouping;
+	guint gcnt = 0;
+	guint scnt = 0;
 
 	g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));
 	g_return_if_fail (node != NULL);
 
-	if (state_version <= 0.05) {
-		i = 0;
-		for (grouping = node->xmlChildrenNode; grouping && !strcmp ((gchar *) grouping->name, "group"); grouping = grouping->xmlChildrenNode) {
-			ETableSortColumn column;
-			column.column = e_xml_get_integer_prop_by_name (grouping, (const guchar *)"column");
-			column.ascending = e_xml_get_bool_prop_by_name (grouping, (const guchar *)"ascending");
-			e_table_sort_info_grouping_set_nth (sort_info, i++, column);
-		}
-		i = 0;
-		for (; grouping && !strcmp ((gchar *) grouping->name, "leaf"); grouping = grouping->xmlChildrenNode) {
-			ETableSortColumn column;
-			column.column = e_xml_get_integer_prop_by_name (grouping, (const guchar *)"column");
-			column.ascending = e_xml_get_bool_prop_by_name (grouping, (const guchar *)"ascending");
-			e_table_sort_info_sorting_set_nth (sort_info, i++, column);
+	specification = e_table_sort_info_ref_specification (sort_info);
+	columns = e_table_specification_ref_columns (specification);
+
+	for (grouping = node->children; grouping; grouping = grouping->next) {
+
+		if (grouping->type != XML_ELEMENT_NODE)
+			continue;
+
+		if (g_str_equal ((gchar *) grouping->name, "group")) {
+			GtkSortType sort_type;
+			gboolean ascending;
+			guint index;
+
+			index = e_xml_get_integer_prop_by_name (
+				grouping, (guchar *) "column");
+			ascending = e_xml_get_bool_prop_by_name (
+				grouping, (guchar *) "ascending");
+
+			if (ascending)
+				sort_type = GTK_SORT_ASCENDING;
+			else
+				sort_type = GTK_SORT_DESCENDING;
+
+			if (index < columns->len)
+				e_table_sort_info_grouping_set_nth (
+					sort_info, gcnt++,
+					columns->pdata[index],
+					sort_type);
 		}
-	} else {
-		guint gcnt = 0;
-		guint scnt = 0;
-		for (grouping = node->children; grouping; grouping = grouping->next) {
-			ETableSortColumn column;
-
-			if (grouping->type != XML_ELEMENT_NODE)
-				continue;
-
-			if (!strcmp ((gchar *) grouping->name, "group")) {
-				column.column = e_xml_get_integer_prop_by_name (grouping, (const guchar *)"column");
-				column.ascending = e_xml_get_bool_prop_by_name (grouping, (const guchar *)"ascending");
-				e_table_sort_info_grouping_set_nth (sort_info, gcnt++, column);
-			} else if (!strcmp ((gchar *) grouping->name, "leaf")) {
-				column.column = e_xml_get_integer_prop_by_name (grouping, (const guchar *)"column");
-				column.ascending = e_xml_get_bool_prop_by_name (grouping, (const guchar *)"ascending");
-				e_table_sort_info_sorting_set_nth (sort_info, scnt++, column);
-			}
+
+		if (g_str_equal ((gchar *) grouping->name, "leaf")) {
+			GtkSortType sort_type;
+			gboolean ascending;
+			gint index;;
+
+			index = e_xml_get_integer_prop_by_name (
+				grouping, (guchar *) "column");
+			ascending = e_xml_get_bool_prop_by_name (
+				grouping, (guchar *) "ascending");
+
+			if (ascending)
+				sort_type = GTK_SORT_ASCENDING;
+			else
+				sort_type = GTK_SORT_DESCENDING;
+
+			if (index < columns->len)
+				e_table_sort_info_sorting_set_nth (
+					sort_info, scnt++,
+					columns->pdata[index],
+				sort_type);
 		}
 	}
+
+	g_object_unref (specification);
+	g_ptr_array_unref (columns);
+
 	g_signal_emit (sort_info, signals[SORT_INFO_CHANGED], 0);
 }
 
@@ -506,40 +579,77 @@ xmlNode *
 e_table_sort_info_save_to_node (ETableSortInfo *sort_info,
                                 xmlNode *parent)
 {
+	ETableSpecification *specification;
 	xmlNode *grouping;
 	guint sort_count;
 	guint group_count;
-	guint i;
+	guint ii;
 
 	g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), NULL);
 
 	sort_count = e_table_sort_info_sorting_get_count (sort_info);
 	group_count = e_table_sort_info_grouping_get_count (sort_info);
 
-	grouping = xmlNewChild (parent, NULL, (const guchar *)"grouping", NULL);
+	grouping = xmlNewChild (parent, NULL, (guchar *) "grouping", NULL);
 
-	for (i = 0; i < group_count; i++) {
-		ETableSortColumn column;
+	specification = e_table_sort_info_ref_specification (sort_info);
+
+	for (ii = 0; ii < group_count; ii++) {
+		ETableColumnSpecification *column_spec;
+		GtkSortType sort_type;
 		xmlNode *new_node;
+		gint index;
+
+		column_spec = e_table_sort_info_grouping_get_nth (
+			sort_info, ii, &sort_type);
+
+		index = e_table_specification_get_column_index (
+			specification, column_spec);
+
+		if (index < 0) {
+			g_warn_if_reached ();
+			continue;
+		}
 
-		column = e_table_sort_info_grouping_get_nth (sort_info, i);
-		new_node = xmlNewChild (grouping, NULL, (const guchar *)"group", NULL);
+		new_node = xmlNewChild (
+			grouping, NULL, (guchar *) "group", NULL);
 
-		e_xml_set_integer_prop_by_name (new_node, (const guchar *)"column", column.column);
-		e_xml_set_bool_prop_by_name (new_node, (const guchar *)"ascending", column.ascending);
+		e_xml_set_integer_prop_by_name (
+			new_node, (guchar *) "column", index);
+		e_xml_set_bool_prop_by_name (
+			new_node, (guchar *) "ascending",
+			(sort_type == GTK_SORT_ASCENDING));
 	}
 
-	for (i = 0; i < sort_count; i++) {
-		ETableSortColumn column;
+	for (ii = 0; ii < sort_count; ii++) {
+		ETableColumnSpecification *column_spec;
+		GtkSortType sort_type;
 		xmlNode *new_node;
+		gint index;
 
-		column = e_table_sort_info_sorting_get_nth (sort_info, i);
-		new_node = xmlNewChild (grouping, NULL, (const guchar *)"leaf", NULL);
+		column_spec = e_table_sort_info_sorting_get_nth (
+			sort_info, ii, &sort_type);
 
-		e_xml_set_integer_prop_by_name (new_node, (const guchar *)"column", column.column);
-		e_xml_set_bool_prop_by_name (new_node, (const guchar *)"ascending", column.ascending);
+		index = e_table_specification_get_column_index (
+			specification, column_spec);
+
+		if (index < 0) {
+			g_warn_if_reached ();
+			continue;
+		}
+
+		new_node = xmlNewChild (
+			grouping, NULL, (guchar *) "leaf", NULL);
+
+		e_xml_set_integer_prop_by_name (
+			new_node, (guchar *) "column", index);
+		e_xml_set_bool_prop_by_name (
+			new_node, (guchar *) "ascending",
+			(sort_type == GTK_SORT_ASCENDING));
 	}
 
+	g_object_unref (specification);
+
 	return grouping;
 }
 
diff --git a/e-util/e-table-sort-info.h b/e-util/e-table-sort-info.h
index 64ed8640e7..583feba67a 100644
--- a/e-util/e-table-sort-info.h
+++ b/e-util/e-table-sort-info.h
@@ -23,9 +23,11 @@
 #ifndef E_TABLE_SORT_INFO_H
 #define E_TABLE_SORT_INFO_H
 
-#include <glib-object.h>
+#include <gtk/gtk.h>
 #include <libxml/tree.h>
 
+#include <e-util/e-table-column-specification.h>
+
 /* Standard GObject macros */
 #define E_TYPE_TABLE_SORT_INFO \
 	(e_table_sort_info_get_type ())
@@ -50,17 +52,10 @@ G_BEGIN_DECLS
 /* Avoid a circular dependency. */
 struct _ETableSpecification;
 
-typedef struct _ETableSortColumn ETableSortColumn;
-
 typedef struct _ETableSortInfo ETableSortInfo;
 typedef struct _ETableSortInfoClass ETableSortInfoClass;
 typedef struct _ETableSortInfoPrivate ETableSortInfoPrivate;
 
-struct _ETableSortColumn {
-	guint column : 31;
-	guint ascending : 1;
-};
-
 struct _ETableSortInfo {
 	GObject parent;
 	ETableSortInfoPrivate *priv;
@@ -74,51 +69,60 @@ struct _ETableSortInfoClass {
 	void		(*group_info_changed)	(ETableSortInfo *sort_info);
 };
 
-GType		e_table_sort_info_get_type	(void) G_GNUC_CONST;
-ETableSortInfo *e_table_sort_info_new		(struct _ETableSpecification *specification);
+GType		e_table_sort_info_get_type
+					(void) G_GNUC_CONST;
+ETableSortInfo *e_table_sort_info_new	(struct _ETableSpecification *specification);
 struct _ETableSpecification *
 		e_table_sort_info_ref_specification
-						(ETableSortInfo *sort_info);
-gboolean	e_table_sort_info_get_can_group (ETableSortInfo *sort_info);
-void		e_table_sort_info_set_can_group	(ETableSortInfo *sort_info,
-						 gboolean can_group);
+					(ETableSortInfo *sort_info);
+gboolean	e_table_sort_info_get_can_group
+					(ETableSortInfo *sort_info);
+void		e_table_sort_info_set_can_group
+					(ETableSortInfo *sort_info,
+					 gboolean can_group);
 guint		e_table_sort_info_grouping_get_count
-						(ETableSortInfo *sort_info);
+					(ETableSortInfo *sort_info);
 void		e_table_sort_info_grouping_truncate
-						(ETableSortInfo *sort_info,
-						 guint length);
-ETableSortColumn
+					(ETableSortInfo *sort_info,
+					 guint length);
+ETableColumnSpecification *
 		e_table_sort_info_grouping_get_nth
-						(ETableSortInfo *sort_info,
-						 guint n);
+					(ETableSortInfo *sort_info,
+					 guint n,
+					 GtkSortType *out_sort_type);
 void		e_table_sort_info_grouping_set_nth
-						(ETableSortInfo *sort_info,
-						 guint n,
-						 ETableSortColumn column);
+					(ETableSortInfo *sort_info,
+					 guint n,
+					 ETableColumnSpecification *spec,
+					 GtkSortType sort_type);
 
 guint		e_table_sort_info_sorting_get_count
-						(ETableSortInfo *sort_info);
+					(ETableSortInfo *sort_info);
 void		e_table_sort_info_sorting_remove
-						(ETableSortInfo *sort_info,
-						 guint n);
+					(ETableSortInfo *sort_info,
+					 guint n);
 void		e_table_sort_info_sorting_truncate
-						(ETableSortInfo *sort_info,
-						 guint length);
-ETableSortColumn
+					(ETableSortInfo *sort_info,
+					 guint length);
+ETableColumnSpecification *
 		e_table_sort_info_sorting_get_nth
-						(ETableSortInfo *sort_info,
-						 guint n);
+					(ETableSortInfo *sort_info,
+					 guint n,
+					 GtkSortType *out_sort_type);
 void		e_table_sort_info_sorting_set_nth
-						(ETableSortInfo *sort_info,
-						 guint n,
-						 ETableSortColumn column);
+					(ETableSortInfo *sort_info,
+					 guint n,
+					 ETableColumnSpecification *spec,
+					 GtkSortType sort_type);
 void		e_table_sort_info_load_from_node
-						(ETableSortInfo *sort_info,
-						 xmlNode *node,
-						 gdouble state_version);
-xmlNode *	e_table_sort_info_save_to_node	(ETableSortInfo *sort_info,
-						 xmlNode *parent);
-ETableSortInfo *e_table_sort_info_duplicate	(ETableSortInfo *sort_info);
+					(ETableSortInfo *sort_info,
+					 xmlNode *node,
+					 gdouble state_version);
+xmlNode *	e_table_sort_info_save_to_node
+					(ETableSortInfo *sort_info,
+					 xmlNode *parent);
+ETableSortInfo *e_table_sort_info_duplicate
+					(ETableSortInfo *sort_info);
 
 G_END_DECLS
 
diff --git a/e-util/e-table-sorter.c b/e-util/e-table-sorter.c
index 1342326c8f..d8e50db13d 100644
--- a/e-util/e-table-sorter.c
+++ b/e-util/e-table-sorter.c
@@ -136,24 +136,36 @@ table_sorter_sort (ETableSorter *table_sorter)
 	qd.cmp_cache = e_table_sorting_utils_create_cmp_cache ();
 
 	for (j = 0; j < cols; j++) {
-		ETableSortColumn column;
+		ETableColumnSpecification *spec;
 		ETableCol *col;
+		GtkSortType sort_type;
 
 		if (j < group_cols)
-			column = e_table_sort_info_grouping_get_nth (table_sorter->sort_info, j);
+			spec = e_table_sort_info_grouping_get_nth (
+				table_sorter->sort_info,
+				j, &sort_type);
 		else
-			column = e_table_sort_info_sorting_get_nth (table_sorter->sort_info, j - group_cols);
-
-		col = e_table_header_get_column_by_col_idx (table_sorter->full_header, column.column);
-		if (col == NULL)
-			col = e_table_header_get_column (table_sorter->full_header, e_table_header_count (table_sorter->full_header) - 1);
+			spec = e_table_sort_info_sorting_get_nth (
+				table_sorter->sort_info,
+				j - group_cols, &sort_type);
+
+		col = e_table_header_get_column_by_spec (
+			table_sorter->full_header, spec);
+		if (col == NULL) {
+			gint last = e_table_header_count (
+				table_sorter->full_header) - 1;
+			col = e_table_header_get_column (
+				table_sorter->full_header, last);
+		}
 
 		for (i = 0; i < rows; i++) {
-			qd.vals[i * cols + j] = e_table_model_value_at (table_sorter->source, col->spec->model_col, i);
+			qd.vals[i * cols + j] = e_table_model_value_at (
+				table_sorter->source,
+				col->spec->model_col, i);
 		}
 
 		qd.compare[j] = col->compare;
-		qd.ascending[j] = column.ascending;
+		qd.ascending[j] = (sort_type == GTK_SORT_ASCENDING);
 	}
 
 	g_qsort_with_data (table_sorter->sorted, rows, sizeof (gint), qsort_callback, &qd);
diff --git a/e-util/e-table-sorting-utils.c b/e-util/e-table-sorting-utils.c
index a8c5bcdf5e..4e0413493b 100644
--- a/e-util/e-table-sorting-utils.c
+++ b/e-util/e-table-sorting-utils.c
@@ -48,10 +48,13 @@ etsu_compare (ETableModel *source,
 	GtkSortType sort_type = GTK_SORT_ASCENDING;
 
 	for (j = 0; j < sort_count; j++) {
-		ETableSortColumn column = e_table_sort_info_sorting_get_nth (sort_info, j);
+		ETableColumnSpecification *spec;
 		ETableCol *col;
 
-		col = e_table_header_get_column_by_col_idx (full_header, column.column);
+		spec = e_table_sort_info_sorting_get_nth (
+			sort_info, j, &sort_type);
+
+		col = e_table_header_get_column_by_spec (full_header, spec);
 		if (col == NULL) {
 			gint last = e_table_header_count (full_header) - 1;
 			col = e_table_header_get_column (full_header, last);
@@ -63,10 +66,6 @@ etsu_compare (ETableModel *source,
 			e_table_model_value_at (
 				source, col->spec->compare_col, row2),
 			cmp_cache);
-		if (column.ascending)
-			sort_type = GTK_SORT_ASCENDING;
-		else
-			sort_type = GTK_SORT_DESCENDING;
 		if (comp_val != 0)
 			break;
 	}
@@ -163,10 +162,13 @@ e_table_sorting_utils_sort (ETableModel *source,
 	closure.cmp_cache = e_table_sorting_utils_create_cmp_cache ();
 
 	for (j = 0; j < cols; j++) {
-		ETableSortColumn column = e_table_sort_info_sorting_get_nth (sort_info, j);
+		ETableColumnSpecification *spec;
 		ETableCol *col;
 
-		col = e_table_header_get_column_by_col_idx (full_header, column.column);
+		spec = e_table_sort_info_sorting_get_nth (
+			sort_info, j, &closure.sort_type[j]);
+
+		col = e_table_header_get_column_by_spec (full_header, spec);
 		if (col == NULL) {
 			gint last = e_table_header_count (full_header) - 1;
 			col = e_table_header_get_column (full_header, last);
@@ -176,10 +178,6 @@ e_table_sorting_utils_sort (ETableModel *source,
 			closure.vals[map_table[i] * cols + j] = e_table_model_value_at (source, col->spec->compare_col, map_table[i]);
 		}
 		closure.compare[j] = col->compare;
-		if (column.ascending)
-			closure.sort_type[j] = GTK_SORT_ASCENDING;
-		else
-			closure.sort_type[j] = GTK_SORT_DESCENDING;
 	}
 
 	g_qsort_with_data (
@@ -205,10 +203,13 @@ e_table_sorting_utils_affects_sort (ETableSortInfo *sort_info,
 	cols = e_table_sort_info_sorting_get_count (sort_info);
 
 	for (j = 0; j < cols; j++) {
-		ETableSortColumn column = e_table_sort_info_sorting_get_nth (sort_info, j);
+		ETableColumnSpecification *spec;
 		ETableCol *col;
 
-		col = e_table_header_get_column_by_col_idx (full_header, column.column);
+		spec = e_table_sort_info_sorting_get_nth (
+			sort_info, j, NULL);
+
+		col = e_table_header_get_column_by_spec (full_header, spec);
 		if (col == NULL) {
 			gint last = e_table_header_count (full_header) - 1;
 			col = e_table_header_get_column (full_header, last);
@@ -291,10 +292,13 @@ etsu_tree_compare (ETreeModel *source,
 	GtkSortType sort_type = GTK_SORT_ASCENDING;
 
 	for (j = 0; j < sort_count; j++) {
-		ETableSortColumn column = e_table_sort_info_sorting_get_nth (sort_info, j);
+		ETableColumnSpecification *spec;
 		ETableCol *col;
 
-		col = e_table_header_get_column_by_col_idx (full_header, column.column);
+		spec = e_table_sort_info_sorting_get_nth (
+			sort_info, j, &sort_type);
+
+		col = e_table_header_get_column_by_spec (full_header, spec);
 		if (col == NULL) {
 			gint last = e_table_header_count (full_header) - 1;
 			col = e_table_header_get_column (full_header, last);
@@ -306,10 +310,6 @@ etsu_tree_compare (ETreeModel *source,
 			e_tree_model_value_at (
 				source, path2, col->spec->compare_col),
 			cmp_cache);
-		if (column.ascending)
-			sort_type = GTK_SORT_ASCENDING;
-		else
-			sort_type = GTK_SORT_DESCENDING;
 		if (comp_val != 0)
 			break;
 	}
@@ -358,10 +358,13 @@ e_table_sorting_utils_tree_sort (ETreeModel *source,
 	closure.cmp_cache = e_table_sorting_utils_create_cmp_cache ();
 
 	for (j = 0; j < cols; j++) {
-		ETableSortColumn column = e_table_sort_info_sorting_get_nth (sort_info, j);
+		ETableColumnSpecification *spec;
 		ETableCol *col;
 
-		col = e_table_header_get_column_by_col_idx (full_header, column.column);
+		spec = e_table_sort_info_sorting_get_nth (
+			sort_info, j, &closure.sort_type[j]);
+
+		col = e_table_header_get_column_by_spec (full_header, spec);
 		if (col == NULL) {
 			gint last = e_table_header_count (full_header) - 1;
 			col = e_table_header_get_column (full_header, last);
@@ -371,10 +374,6 @@ e_table_sorting_utils_tree_sort (ETreeModel *source,
 			closure.vals[i * cols + j] = e_tree_model_sort_value_at (source, map_table[i], col->spec->compare_col);
 		}
 		closure.compare[j] = col->compare;
-		if (column.ascending)
-			closure.sort_type[j] = GTK_SORT_ASCENDING;
-		else
-			closure.sort_type[j] = GTK_SORT_DESCENDING;
 	}
 
 	map = g_new (int, count);
diff --git a/e-util/e-table-utils.c b/e-util/e-table-utils.c
index 040e5d3e07..a3b8b928b4 100644
--- a/e-util/e-table-utils.c
+++ b/e-util/e-table-utils.c
@@ -174,37 +174,33 @@ e_table_util_calculate_current_search_col (ETableHeader *header,
 	count = e_table_sort_info_grouping_get_count (sort_info);
 
 	for (i = 0; i < count; i++) {
-		ETableSortColumn column;
+		ETableColumnSpecification *spec;
 
-		column = e_table_sort_info_grouping_get_nth (sort_info, i);
+		spec = e_table_sort_info_grouping_get_nth (sort_info, i, NULL);
+		col = e_table_header_get_column_by_spec (full_header, spec);
 
-		col = e_table_header_get_column (full_header, column.column);
-
-		if (col && col->search)
-			break;
+		if (col != NULL && col->search)
+			return col;
 
 		col = NULL;
 	}
 
-	if (col == NULL) {
-		count = e_table_sort_info_sorting_get_count (sort_info);
-		for (i = 0; i < count; i++) {
-			ETableSortColumn column;
-
-			column = e_table_sort_info_sorting_get_nth (sort_info, i);
+	count = e_table_sort_info_sorting_get_count (sort_info);
+	for (i = 0; i < count; i++) {
+		ETableColumnSpecification *spec;
 
-			col = e_table_header_get_column (full_header, column.column);
+		spec = e_table_sort_info_sorting_get_nth (sort_info, i, NULL);
+		col = e_table_header_get_column_by_spec (full_header, spec);
 
-			if (col && col->search)
-				break;
+		if (col != NULL && col->search)
+			return col;
 
-			col = NULL;
-		}
+		col = NULL;
 	}
 
-	if (col == NULL && always_search) {
-		col = e_table_header_prioritized_column_selected (header, check_col, NULL);
-	}
+	if (always_search)
+		col = e_table_header_prioritized_column_selected (
+			header, check_col, NULL);
 
 	return col;
 }
diff --git a/mail/message-list.c b/mail/message-list.c
index 7ce74121a1..cf8f99ecc1 100644
--- a/mail/message-list.c
+++ b/mail/message-list.c
@@ -5053,7 +5053,7 @@ message_list_set_search (MessageList *message_list,
 
 struct sort_column_data {
 	ETableCol *col;
-	gboolean ascending;
+	GtkSortType sort_type;
 };
 
 struct sort_message_info_data {
@@ -5128,7 +5128,7 @@ cmp_array_uids (gconstpointer a,
 			res = v1 == NULL ? -1 : 1;
 		}
 
-		if (!scol->ascending)
+		if (scol->sort_type == GTK_SORT_DESCENDING)
 			res = res * (-1);
 	}
 
@@ -5198,15 +5198,19 @@ ml_sort_uids_by_tree (MessageList *message_list,
 	     i < len
 	     && !g_cancellable_is_cancelled (cancellable);
 	     i++) {
-		ETableSortColumn scol;
-		struct sort_column_data *data = g_new0 (struct sort_column_data, 1);
+		ETableColumnSpecification *spec;
+		struct sort_column_data *data;
 
-		scol = e_table_sort_info_sorting_get_nth (sort_info, i);
+		data = g_new0 (struct sort_column_data, 1);
 
-		data->ascending = scol.ascending;
-		data->col = e_table_header_get_column_by_col_idx (full_header, scol.column);
-		if (data->col == NULL)
-			data->col = e_table_header_get_column (full_header, e_table_header_count (full_header) - 1);
+		spec = e_table_sort_info_sorting_get_nth (
+			sort_info, i, &data->sort_type);
+
+		data->col = e_table_header_get_column_by_spec (full_header, spec);
+		if (data->col == NULL) {
+			gint last = e_table_header_count (full_header) - 1;
+			data->col = e_table_header_get_column (full_header, last);
+		}
 
 		g_ptr_array_add (sort_data.sort_columns, data);
 	}