[gnumeric] Fix export of non-ODF interpolation types to ODF.

[Andreas J. Guelzow <guelzow src gnome org>]

commit bc3c81a2e466794a1ded3387ec4639a23e79eb97
Author: Andreas J. Guelzow <aguelzow pyrshep ca>
Date:   Mon May 19 12:47:47 2014 -0600

    Fix export of non-ODF interpolation types to ODF.
    
    2014-05-19  Andreas J. Guelzow <aguelzow pyrshep ca>
    
        * openoffice-write.c (od_style_prop_chart): use gnm:interpolation rather
        than using an invalid attirbute value with chart:interpolation
        * openoffice-read.c (od_style_prop_chart): handle gnm:interpolation

 NEWS                                  |    1 +
 plugins/openoffice/ChangeLog          |    6 ++++++
 plugins/openoffice/openoffice-read.c  |   11 +++++++----
 plugins/openoffice/openoffice-write.c |    2 +-
 4 files changed, 15 insertions(+), 5 deletions(-)
---
diff --git a/NEWS b/NEWS
index bdc8ab2..061f4e7 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,7 @@ Gnumeric 1.12.16
 Andreas:
        * Fix database-range import from ODF. [#730197]
        * Improve chart roundtrip through ODF. [#728197]
+       * Fix export of non-ODF interpolation types to ODF.
 
 Morten:
        * Start moving off GtkUIManager.
diff --git a/plugins/openoffice/ChangeLog b/plugins/openoffice/ChangeLog
index c33dbf1..91baa81 100644
--- a/plugins/openoffice/ChangeLog
+++ b/plugins/openoffice/ChangeLog
@@ -1,3 +1,9 @@
+2014-05-19  Andreas J. Guelzow <aguelzow pyrshep ca>
+
+       * openoffice-write.c (od_style_prop_chart): use gnm:interpolation rather
+       than using an invalid attirbute value with chart:interpolation
+       * openoffice-read.c (od_style_prop_chart): handle gnm:interpolation
+
 2014-05-18  Morten Welinder  <terra gnome org>
 
        * openoffice-read.c (odf_apply_style_props): For markers, map only
diff --git a/plugins/openoffice/openoffice-read.c b/plugins/openoffice/openoffice-read.c
index 53e2841..3557212 100644
--- a/plugins/openoffice/openoffice-read.c
+++ b/plugins/openoffice/openoffice-read.c
@@ -6865,6 +6865,8 @@ od_style_prop_chart (GsfXMLIn *xin, xmlChar const **attrs)
        gboolean stacked_unset = FALSE;
        gboolean overlap_set = FALSE;
        gboolean percentage_set = FALSE;
+       char const *interpolation = NULL;
+
 
        g_return_if_fail (style != NULL ||
                          state->default_style.cells != NULL);
@@ -7007,10 +7009,11 @@ od_style_prop_chart (GsfXMLIn *xin, xmlChar const **attrs)
                        style->style_props = g_slist_prepend
                                (style->style_props,
                                 oo_prop_new_double ("symbol-height", ftmp));
-               } else if (gsf_xml_in_namecmp (xin, CXML2C (attrs[0]),
-                                              OO_NS_CHART, "interpolation")) {
-                       char const *interpolation = NULL;
-
+               } else if ((interpolation == NULL) &&
+                          (gsf_xml_in_namecmp (xin, CXML2C (attrs[0]),
+                                              OO_NS_CHART, "interpolation") ||
+                          gsf_xml_in_namecmp (xin, CXML2C (attrs[0]),
+                                              OO_GNUM_NS_EXT, "interpolation"))) {
                        if (attr_eq (attrs[1], "none"))
                                interpolation = "linear";
                        else if (attr_eq (attrs[1], "b-spline")) {
diff --git a/plugins/openoffice/openoffice-write.c b/plugins/openoffice/openoffice-write.c
index 6049ffc..ebb88a6 100644
--- a/plugins/openoffice/openoffice-write.c
+++ b/plugins/openoffice/openoffice-write.c
@@ -6487,7 +6487,7 @@ odf_write_interpolation_attribute (GnmOOExport *state,
                else if (state->with_extension) {
                        char *tag = g_strdup_printf ("gnm:%s", interpolation);
                        gsf_xml_out_add_cstr
-                               (state->xml, CHART "interpolation", tag);
+                               (state->xml, GNMSTYLE "interpolation", tag);
                        g_free (tag);
                } else
                        gsf_xml_out_add_cstr