[gnumeric] xlsx: adhere to schema.

[Morten Welinder <mortenw src gnome org>]

commit 1a8ae0e887d91fa8be7fb84aa8d3dad9ff0546d1
Author: Morten Welinder <terra gnome org>
Date:   Fri Feb 27 12:38:59 2015 -0500

    xlsx: adhere to schema.

 plugins/excel/xlsx-write-drawing.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/plugins/excel/xlsx-write-drawing.c b/plugins/excel/xlsx-write-drawing.c
index 76f5f8c..ddaa1fd 100644
--- a/plugins/excel/xlsx-write-drawing.c
+++ b/plugins/excel/xlsx-write-drawing.c
@@ -920,12 +920,14 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
                }
                if (set_invert)
                        xlsx_write_chart_uint (xml, "c:invertIfNegative", 1, 0);
+               if (explosion > 0.)
+                       xlsx_write_chart_uint (xml, "c:explosion", 0, (unsigned) (explosion * 100));
 
                children = gog_object_get_children (GOG_OBJECT (ser), NULL);
 
                for (l = children; l; l = l->next) {
                        GogObject *pt = l->data;
-                       unsigned idx;
+                       int idx;
                        GOStyle *style;
                        XLSXStyleContext sctx;
 
@@ -935,7 +937,7 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
                        gsf_xml_out_start_element (xml, "c:dPt");
 
                        g_object_get (pt, "index", &idx, NULL);
-                       xlsx_write_chart_uint (xml, "c:idx", 0, idx);
+                       xlsx_write_chart_int (xml, "c:idx", -1, MAX (0, idx));
 
                        xlsx_style_context_init (&sctx, state);
                        sctx.def_has_markers = TRUE;
@@ -994,8 +996,6 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
                }
                g_slist_free (children);
 
-               if (explosion > 0.)
-                       xlsx_write_chart_uint (xml, "c:explosion", 0, (unsigned) (explosion * 100));
                if (use_xy) {
                        xlsx_write_series_dim (state, xml, ser, "c:xVal", GOG_MS_DIM_CATEGORIES);
                        xlsx_write_series_dim (state, xml, ser, "c:yVal", GOG_MS_DIM_VALUES);