Fix/mute issues found by Coverity scan

This makes the code free of Coverity scan issues.
It is sometimes quite pedantic and expects/suggests some
coding habits, thus certain changes may look weird, but for a good
thing, I hope. The code is also tagged with Coverity scan
suppressions, to keep the code as is and hide the warning too.
Also note that Coverity treats g_return_if_fail(), g_assert() and
similar macros as unreliable, and it's true these can be disabled
during the compile time, thus it brings in other set of 'weird'
changes.

22 files changed, 112 insertions, 82 deletions

diff --git a/e-util/e-attachment-store.c b/e-util/e-attachment-store.c
index 3720baf16b..c7128ec182 100644
--- a/e-util/e-attachment-store.c
+++ b/e-util/e-attachment-store.c
@@ -824,8 +824,10 @@ e_attachment_store_get_uris_finish (EAttachmentStore *store,
 	g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (result), NULL);
 
 	simple = G_SIMPLE_ASYNC_RESULT (result);
+	if (g_simple_async_result_propagate_error (simple, error))
+		return NULL;
+
 	uris = g_simple_async_result_get_op_res_gpointer (simple);
-	g_simple_async_result_propagate_error (simple, error);
 
 	return uris;
 }
@@ -982,8 +984,8 @@ e_attachment_store_load_finish (EAttachmentStore *store,
 	g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (result), FALSE);
 
 	simple = G_SIMPLE_ASYNC_RESULT (result);
-	success = g_simple_async_result_get_op_res_gboolean (simple);
-	g_simple_async_result_propagate_error (simple, error);
+	success = !g_simple_async_result_propagate_error (simple, error) &&
+		   g_simple_async_result_get_op_res_gboolean (simple);
 
 	return success;
 }
@@ -1332,8 +1334,10 @@ e_attachment_store_save_finish (EAttachmentStore *store,
 	g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (result), NULL);
 
 	simple = G_SIMPLE_ASYNC_RESULT (result);
+	if (g_simple_async_result_propagate_error (simple, error))
+		return NULL;
+
 	uris = g_simple_async_result_get_op_res_gpointer (simple);
-	g_simple_async_result_propagate_error (simple, error);
 
 	return uris;
 }
diff --git a/e-util/e-attachment.c b/e-util/e-attachment.c
index e2b64ab92b..42d5e93caf 100644
--- a/e-util/e-attachment.c
+++ b/e-util/e-attachment.c
@@ -2191,6 +2191,11 @@ e_attachment_load_finish (EAttachment *attachment,
 	g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (result), FALSE);
 
 	simple = G_SIMPLE_ASYNC_RESULT (result);
+	if (g_simple_async_result_propagate_error (simple, error)) {
+		attachment_set_loading (attachment, FALSE);
+		return FALSE;
+	}
+
 	load_context = g_simple_async_result_get_op_res_gpointer (simple);
 
 	if (load_context != NULL && load_context->mime_part != NULL) {
@@ -2206,8 +2211,6 @@ e_attachment_load_finish (EAttachment *attachment,
 			attachment, load_context->mime_part);
 	}
 
-	g_simple_async_result_propagate_error (simple, error);
-
 	attachment_set_loading (attachment, FALSE);
 
 	return (load_context != NULL);
@@ -2529,8 +2532,8 @@ e_attachment_open_finish (EAttachment *attachment,
 	g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (result), FALSE);
 
 	simple = G_SIMPLE_ASYNC_RESULT (result);
-	success = g_simple_async_result_get_op_res_gboolean (simple);
-	g_simple_async_result_propagate_error (simple, error);
+	success = !g_simple_async_result_propagate_error (simple, error) &&
+		   g_simple_async_result_get_op_res_gboolean (simple);
 
 	return success;
 }
@@ -3066,10 +3069,14 @@ e_attachment_save_finish (EAttachment *attachment,
 	g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (result), NULL);
 
 	simple = G_SIMPLE_ASYNC_RESULT (result);
+	if (g_simple_async_result_propagate_error (simple, error)) {
+		attachment_set_saving (attachment, FALSE);
+		return NULL;
+	}
+
 	destination = g_simple_async_result_get_op_res_gpointer (simple);
 	if (destination != NULL)
 		g_object_ref (destination);
-	g_simple_async_result_propagate_error (simple, error);
 
 	attachment_set_saving (attachment, FALSE);
 
diff --git a/e-util/e-canvas-background.c b/e-util/e-canvas-background.c
index 6379697719..0c5c28a282 100644
--- a/e-util/e-canvas-background.c
+++ b/e-util/e-canvas-background.c
@@ -121,13 +121,13 @@ ecb_set_property (GObject *object,
 
 	switch (property_id) {
 	case PROP_FILL_COLOR:
-		if (g_value_get_string (value))
-			gdk_color_parse (g_value_get_string (value), &color);
-
-		ecb->priv->rgba = ((color.red & 0xff00) << 16 |
-				   (color.green & 0xff00) << 8 |
-				   (color.blue & 0xff00) |
-				   0xff);
+		if (g_value_get_string (value) &&
+		    gdk_color_parse (g_value_get_string (value), &color)) {
+			ecb->priv->rgba = ((color.red & 0xff00) << 16 |
+					   (color.green & 0xff00) << 8 |
+					   (color.blue & 0xff00) |
+					   0xff);
+		}
 		break;
 
 	case PROP_FILL_COLOR_GDK:
diff --git a/e-util/e-canvas.c b/e-util/e-canvas.c
index 93304065e3..2bac10fac6 100644
--- a/e-util/e-canvas.c
+++ b/e-util/e-canvas.c
@@ -678,14 +678,12 @@ e_canvas_item_grab_focus (GnomeCanvasItem *item,
 		gtk_widget_grab_focus (GTK_WIDGET (item->canvas));
 	}
 
-	if (item) {
-		ev.focus_change.type = GDK_FOCUS_CHANGE;
-		ev.focus_change.window = bin_window;
-		ev.focus_change.send_event = FALSE;
-		ev.focus_change.in = TRUE;
+	ev.focus_change.type = GDK_FOCUS_CHANGE;
+	ev.focus_change.window = bin_window;
+	ev.focus_change.send_event = FALSE;
+	ev.focus_change.in = TRUE;
 
-		canvas_emit_event (item->canvas, &ev);
-	}
+	canvas_emit_event (item->canvas, &ev);
 }
 
 static void
diff --git a/e-util/e-cell-text.c b/e-util/e-cell-text.c
index 6026185e9a..d7e38ebe9c 100644
--- a/e-util/e-cell-text.c
+++ b/e-util/e-cell-text.c
@@ -467,7 +467,7 @@ layout_with_preedit (ECellTextView *text_view,
 		edit->im_context,
 		&preedit_string,&preedit_attrs,
 		NULL);
-	preedit_length = edit->preedit_length = strlen (preedit_string);;
+	preedit_length = edit->preedit_length = preedit_string ? strlen (preedit_string) : 0;
 
 	layout = edit->layout;
 
@@ -2237,12 +2237,10 @@ _get_position (ECellTextView *text_view,
 	case E_TEP_BACKWARD_PAGE:
 		return edit->selection_end;
 	default:
-		return edit->selection_end;
+		break;
 	}
 
-	g_return_val_if_reached (0);
-
-	return 0; /* Kill warning */
+	return edit->selection_end;
 }
 
 static void
diff --git a/e-util/e-filter-color.c b/e-util/e-filter-color.c
index 213530fbb2..63c27b7079 100644
--- a/e-util/e-filter-color.c
+++ b/e-util/e-filter-color.c
@@ -84,7 +84,8 @@ filter_color_xml_decode (EFilterElement *element,
 
 	prop = xmlGetProp (node, (xmlChar *)"spec");
 	if (prop != NULL) {
-		gdk_color_parse ((gchar *) prop, &fc->color);
+		if (!gdk_color_parse ((gchar *) prop, &fc->color))
+			g_warning ("%s: Failed to parse color from string '%s'", G_STRFUNC, prop);
 		xmlFree (prop);
 	} else {
 		/* try reading the old RGB properties */
diff --git a/e-util/e-filter-rule.c b/e-util/e-filter-rule.c
index 8dc9a17a8a..842cf63061 100644
--- a/e-util/e-filter-rule.c
+++ b/e-util/e-filter-rule.c
@@ -100,7 +100,11 @@ part_combobox_changed (GtkComboBox *combobox,
 		/* traverse until reached index */
 	}
 
-	g_return_if_fail (part != NULL);
+	if (!part) {
+		g_warn_if_reached ();
+		return;
+	}
+
 	g_return_if_fail (i == index);
 
 	/* dont update if we haven't changed */
diff --git a/e-util/e-misc-utils.c b/e-util/e-misc-utils.c
index 1ae9301aa3..1e9cd1d0c1 100644
--- a/e-util/e-misc-utils.c
+++ b/e-util/e-misc-utils.c
@@ -1232,6 +1232,7 @@ e_format_number (gint number)
 		default:
 			last_count = *grouping;
 			grouping++;
+			/* coverity[fallthrough] */
 		case 0:
 			divider = epow10 (last_count);
 			if (number >= divider) {
diff --git a/e-util/e-name-selector-list.c b/e-util/e-name-selector-list.c
index 52516a5621..8e51e41667 100644
--- a/e-util/e-name-selector-list.c
+++ b/e-util/e-name-selector-list.c
@@ -465,8 +465,9 @@ enl_tree_button_press_event (GtkWidget *widget,
 	if (!gtk_widget_has_grab (GTK_WIDGET (list->priv->popup)))
 		enl_popup_grab (list, (GdkEvent *) event);
 
-	gtk_tree_view_get_dest_row_at_pos (
-		tree_view, event->x, event->y, &path, NULL);
+	if (!gtk_tree_view_get_dest_row_at_pos (
+		tree_view, event->x, event->y, &path, NULL))
+		return FALSE;
 	selection = gtk_tree_view_get_selection (tree_view);
 	if (!gtk_tree_model_get_iter (GTK_TREE_MODEL (store), &iter, path))
 		return FALSE;
diff --git a/e-util/e-send-options.c b/e-util/e-send-options.c
index f586f36f66..c105571f1c 100644
--- a/e-util/e-send-options.c
+++ b/e-util/e-send-options.c
@@ -573,6 +573,7 @@ setup_widgets (ESendOptionsDialog *sod,
 			priv->help_section = g_strdup ("groupwise-placeholder");
 			gtk_widget_hide (priv->completed_label);
 			gtk_widget_hide (priv->when_completed);
+			break;
 		case E_ITEM_TASK:
 			priv->help_section = g_strdup ("groupwise-placeholder");
 			gtk_widget_hide (priv->security_label);
@@ -636,6 +637,7 @@ e_send_options_cb (GtkDialog *dialog,
 	switch (state) {
 		case GTK_RESPONSE_OK:
 			e_send_options_get_widgets_data (sod);
+			/* coverity[fallthrough] */
 		case GTK_RESPONSE_CANCEL:
 			gtk_widget_hide (priv->main);
 			gtk_widget_destroy (priv->main);
diff --git a/e-util/e-stock-request.c b/e-util/e-stock-request.c
index 0ce7d8c254..b8cb21ba87 100644
--- a/e-util/e-stock-request.c
+++ b/e-util/e-stock-request.c
@@ -107,8 +107,11 @@ handle_stock_request_idle_cb (gpointer user_data)
 
 		filename = gtk_icon_info_get_filename (icon_info);
 		if (filename != NULL) {
-			g_file_get_contents (
-				filename, &buffer, &buff_len, &local_error);
+			if (!g_file_get_contents (
+				filename, &buffer, &buff_len, &local_error)) {
+				buffer = NULL;
+				buff_len = 0;
+			}
 			priv->content_type =
 				g_content_type_guess (filename, NULL, 0, NULL);
 
diff --git a/e-util/e-table-click-to-add.c b/e-util/e-table-click-to-add.c
index d5202f7a03..c9abf037c5 100644
--- a/e-util/e-table-click-to-add.c
+++ b/e-util/e-table-click-to-add.c
@@ -437,6 +437,7 @@ etcta_event (GnomeCanvasItem *item,
 	case GDK_FOCUS_CHANGE:
 		if (!e->focus_change.in)
 			return TRUE;
+		/* coverity[fallthrough] */
 
 	case GDK_BUTTON_PRESS:
 		if (etcta->text) {
diff --git a/e-util/e-table-config.c b/e-util/e-table-config.c
index 5fbb6b0329..8c5fecd90a 100644
--- a/e-util/e-table-config.c
+++ b/e-util/e-table-config.c
@@ -231,7 +231,7 @@ static ETableColumnSpecification *
 find_column_spec_by_name (ETableSpecification *spec,
                           const gchar *s)
 {
-	ETableColumnSpecification *column;
+	ETableColumnSpecification *column = NULL;
 	GPtrArray *array;
 	guint ii;
 
diff --git a/e-util/e-table-group-container.c b/e-util/e-table-group-container.c
index d828ddec3e..426c544a63 100644
--- a/e-util/e-table-group-container.c
+++ b/e-util/e-table-group-container.c
@@ -1453,7 +1453,7 @@ e_table_group_container_print_page (EPrintable *ep,
 			break;
 		}
 
-		child = child->next;
+		child = child ? child->next : NULL;
 		if (!child) {
 			child_printable = NULL;
 			break;
diff --git a/e-util/e-table-header-item.c b/e-util/e-table-header-item.c
index 06d003007b..556c8a2e35 100644
--- a/e-util/e-table-header-item.c
+++ b/e-util/e-table-header-item.c
@@ -1222,7 +1222,7 @@ static void
 ethi_start_drag (ETableHeaderItem *ethi,
                  GdkEvent *event)
 {
-	GtkWidget *widget = GTK_WIDGET (GNOME_CANVAS_ITEM (ethi)->canvas);
+	GtkWidget *widget;
 	GtkTargetList *list;
 	GdkDragContext *context;
 	ETableCol *ecol;
diff --git a/e-util/e-table-header-utils.c b/e-util/e-table-header-utils.c
index 66efb01d30..5baf7f1a37 100644
--- a/e-util/e-table-header-utils.c
+++ b/e-util/e-table-header-utils.c
@@ -272,6 +272,7 @@ e_table_header_draw_button (cairo_t *cr,
 		break;
 	}
 
+	/* coverity[dead_error_begin] */
 	default:
 		cairo_restore (cr);
 		g_return_if_reached ();
diff --git a/e-util/e-table-item.c b/e-util/e-table-item.c
index 3f88d8cb7e..1a1956fdcc 100644
--- a/e-util/e-table-item.c
+++ b/e-util/e-table-item.c
@@ -3076,9 +3076,12 @@ eti_event (GnomeCanvasItem *item,
 				e_table_item_leave_edit_(eti);
 			}
 		}
+		return_val = FALSE;
+		break;
 
 	default:
 		return_val = FALSE;
+		break;
 	}
 	/* d(g_print("%s: returning: %s\n", __FUNCTION__, return_val?"true":"false"));*/
 
@@ -3601,9 +3604,11 @@ e_table_item_enter_edit (ETableItem *eti,
 	eti->editing_col = col;
 	eti->editing_row = row;
 
-	eti->edit_ctx = e_cell_enter_edit (eti->cell_views[col], view_to_model_col (eti, col), col, row);
+	if (col >= 0) {
+		eti->edit_ctx = e_cell_enter_edit (eti->cell_views[col], view_to_model_col (eti, col), col, row);
 
-	g_object_notify (G_OBJECT (eti), "is-editing");
+		g_object_notify (G_OBJECT (eti), "is-editing");
+	}
 }
 
 /**
diff --git a/e-util/e-text.c b/e-util/e-text.c
index d13b4a637e..3fda17268d 100644
--- a/e-util/e-text.c
+++ b/e-util/e-text.c
@@ -726,8 +726,11 @@ e_text_set_property (GObject *object,
 		break;
 
 	case PROP_FILL_COLOR:
-		if (g_value_get_string (value))
-			gdk_color_parse (g_value_get_string (value), &color);
+		if (g_value_get_string (value) &&
+		    !gdk_color_parse (g_value_get_string (value), &color)) {
+			g_warning ("%s: Failed to parse color '%s'", G_STRFUNC, g_value_get_string (value));
+			break;
+		}
 
 		text->rgba = ((color.red & 0xff00) << 16 |
 			      (color.green & 0xff00) << 8 |
@@ -1275,7 +1278,7 @@ e_text_draw (GnomeCanvasItem *item,
 
 	if (text->editing) {
 		if (text->selection_start != text->selection_end) {
-			cairo_region_t *clip_region = cairo_region_create ();
+			cairo_region_t *clip_region;
 			gint indices[2];
 			GtkStateType state;
 
diff --git a/e-util/gal-a11y-e-cell-tree.c b/e-util/gal-a11y-e-cell-tree.c
index e0757f5300..07d6ac331b 100644
--- a/e-util/gal-a11y-e-cell-tree.c
+++ b/e-util/gal-a11y-e-cell-tree.c
@@ -191,15 +191,14 @@ gal_a11y_e_cell_tree_new (ETableItem *item,
 {
 	AtkObject *subcell_a11y;
 	GalA11yECellTree *a11y;
-
 	ETreePath node;
 	ETreeModel *tree_model;
 	ETreeTableAdapter *tree_table_adapter;
-
 	ECellView *subcell_view;
+
 	subcell_view = e_cell_tree_view_get_subcell_view (cell_view);
 
-	if (subcell_view->ecell) {
+	if (subcell_view && subcell_view->ecell) {
 		subcell_a11y = gal_a11y_e_cell_registry_get_object (
 			NULL,
 			item,
@@ -233,8 +232,7 @@ gal_a11y_e_cell_tree_new (ETableItem *item,
 			if (e_tree_table_adapter_node_is_expanded (tree_table_adapter, node))
 				gal_a11y_e_cell_add_state (GAL_A11Y_E_CELL (subcell_a11y), ATK_STATE_EXPANDED, FALSE);
 		}
-	}
-	else
+	} else
 		subcell_a11y = NULL;
 
 	/* create a companion a11y object, this object has type GalA11yECellTree
diff --git a/e-util/gal-a11y-e-cell.c b/e-util/gal-a11y-e-cell.c
index 9f16b34fd9..b05f38d750 100644
--- a/e-util/gal-a11y-e-cell.c
+++ b/e-util/gal-a11y-e-cell.c
@@ -359,7 +359,10 @@ gal_a11y_e_cell_remove_action_by_name (GalA11yECell *cell,
 		}
 	}
 
-	g_return_val_if_fail (list_node != NULL, FALSE);
+	if (!list_node) {
+		g_warn_if_reached ();
+		return FALSE;
+	}
 
 	_gal_a11y_e_cell_destroy_action_info (list_node->data, NULL);
 	cell->action_list = g_list_remove_link (cell->action_list, list_node);
diff --git a/e-util/gal-a11y-e-table-item.c b/e-util/gal-a11y-e-table-item.c
index 51bce1725b..c3bbded403 100644
--- a/e-util/gal-a11y-e-table-item.c
+++ b/e-util/gal-a11y-e-table-item.c
@@ -1141,41 +1141,38 @@ gal_a11y_e_table_item_new (ETableItem *item)
 	if (GET_PRIVATE (a11y)->columns == NULL)
 		return NULL;
 
-	if (item) {
-		g_signal_connect (
-			item, "selection_model_removed",
-			G_CALLBACK (eti_a11y_selection_model_removed_cb), NULL);
+	g_signal_connect (
+		item, "selection_model_removed",
+		G_CALLBACK (eti_a11y_selection_model_removed_cb), NULL);
+	g_signal_connect (
+		item, "selection_model_added",
+		G_CALLBACK (eti_a11y_selection_model_added_cb), NULL);
+	if (item->selection)
+		gal_a11y_e_table_item_ref_selection (
+			a11y,
+			item->selection);
+
+	/* find the TableItem's parent: table or tree */
+	GET_PRIVATE (a11y)->widget = gtk_widget_get_parent (
+		GTK_WIDGET (item->parent.canvas));
+	parent = gtk_widget_get_accessible (GET_PRIVATE (a11y)->widget);
+	name = atk_object_get_name (parent);
+	if (name)
+		atk_object_set_name (accessible, name);
+	atk_object_set_parent (accessible, parent);
+
+	if (E_IS_TREE (GET_PRIVATE (a11y)->widget)) {
+		ETreeModel *model;
+		model = e_tree_get_model (E_TREE (GET_PRIVATE (a11y)->widget));
 		g_signal_connect (
-			item, "selection_model_added",
-			G_CALLBACK (eti_a11y_selection_model_added_cb), NULL);
-		if (item->selection)
-			gal_a11y_e_table_item_ref_selection (
-				a11y,
-				item->selection);
-
-		/* find the TableItem's parent: table or tree */
-		GET_PRIVATE (a11y)->widget = gtk_widget_get_parent (
-			GTK_WIDGET (item->parent.canvas));
-		parent = gtk_widget_get_accessible (GET_PRIVATE (a11y)->widget);
-		name = atk_object_get_name (parent);
-		if (name)
-			atk_object_set_name (accessible, name);
-		atk_object_set_parent (accessible, parent);
-
-		if (E_IS_TREE (GET_PRIVATE (a11y)->widget)) {
-			ETreeModel *model;
-			model = e_tree_get_model (E_TREE (GET_PRIVATE (a11y)->widget));
-			g_signal_connect (
-				model, "node_changed",
-				G_CALLBACK (eti_tree_model_node_changed_cb), item);
-			accessible->role = ATK_ROLE_TREE_TABLE;
-		} else if (E_IS_TABLE (GET_PRIVATE (a11y)->widget)) {
-			accessible->role = ATK_ROLE_TABLE;
-		}
+			model, "node_changed",
+			G_CALLBACK (eti_tree_model_node_changed_cb), item);
+		accessible->role = ATK_ROLE_TREE_TABLE;
+	} else if (E_IS_TABLE (GET_PRIVATE (a11y)->widget)) {
+		accessible->role = ATK_ROLE_TABLE;
 	}
 
-	if (item)
-		g_object_weak_ref (G_OBJECT (item), item_finalized, g_object_ref (a11y));
+	g_object_weak_ref (G_OBJECT (item), item_finalized, g_object_ref (a11y));
 
 	esm = item->selection;
 
diff --git a/e-util/test-calendar.c b/e-util/test-calendar.c
index 9d36e9027a..790b710104 100644
--- a/e-util/test-calendar.c
+++ b/e-util/test-calendar.c
@@ -108,10 +108,13 @@ on_date_range_changed (ECalendarItem *calitem)
 	gint start_year, start_month, start_day;
 	gint end_year, end_month, end_day;
 
-	e_calendar_item_get_date_range (
+	if (!e_calendar_item_get_date_range (
 		calitem,
 		&start_year, &start_month, &start_day,
-		&end_year, &end_month, &end_day);
+		&end_year, &end_month, &end_day)) {
+		g_warning ("%s: Failed to get date range", G_STRFUNC);
+		return;
+	}
 
 	g_print (
 		"Date range changed (D/M/Y): %i/%i/%i - %i/%i/%i\n",