[gnumeric] xlsx: don't use truncated pointers as axis ids.

[Morten Welinder <mortenw src gnome org>]

commit a92413cba8cb6f134b71732324b88c83439f9fe2
Author: Morten Welinder <terra gnome org>
Date:   Sat Jan 17 20:09:06 2015 -0500

    xlsx: don't use truncated pointers as axis ids.
    
    Avoid using lower-32-bits-of-pointer as numeric ids.  Use reproducible
    indices instead.

 plugins/excel/ChangeLog            |    3 +++
 plugins/excel/xlsx-write-drawing.c |   17 ++++++++++++++---
 plugins/excel/xlsx-write.c         |    4 ++++
 3 files changed, 21 insertions(+), 3 deletions(-)
---
diff --git a/plugins/excel/ChangeLog b/plugins/excel/ChangeLog
index 616faed..1ba323d 100644
--- a/plugins/excel/ChangeLog
+++ b/plugins/excel/ChangeLog
@@ -1,5 +1,8 @@
 2015-01-17  Morten Welinder  <terra gnome org>
 
+       * xlsx-write-drawing.c (xlsx_get_axid): New function allowing us
+       to get away from storing truncated pointers as axis ids.
+
        * xlsx-read-drawing.c (xlsx_chart_bar_overlap)
        (xlsx_chart_bar_gap): Fix reading percentages.
        (xlsx_chart_no_fill): Handle noFill when used to avoid lines
diff --git a/plugins/excel/xlsx-write-drawing.c b/plugins/excel/xlsx-write-drawing.c
index 58cc111..ce53c1d 100644
--- a/plugins/excel/xlsx-write-drawing.c
+++ b/plugins/excel/xlsx-write-drawing.c
@@ -301,6 +301,17 @@ xlsx_write_chart_text (XLSXWriteState *state, GsfXMLOut *xml,
        g_free (text);
 }
 
+static unsigned
+xlsx_get_axid (XLSXWriteState *state, GogAxis *axis)
+{
+       gpointer l = g_hash_table_lookup (state->axids, axis);
+       if (!l) {
+               l = GUINT_TO_POINTER (1 + g_hash_table_size (state->axids));
+               g_hash_table_insert (state->axids, axis, l);
+       }
+       return GPOINTER_TO_UINT (l);
+}
+
 
 static void
 xlsx_write_axis (XLSXWriteState *state, GsfXMLOut *xml, GogAxis *axis, GogAxisType at)
@@ -315,7 +326,7 @@ xlsx_write_axis (XLSXWriteState *state, GsfXMLOut *xml, GogAxis *axis, GogAxisTy
                gsf_xml_out_start_element (xml, "c:catAx");
        else
                gsf_xml_out_start_element (xml, "c:valAx");
-       xlsx_write_chart_int (xml, "c:axId", 0, GPOINTER_TO_UINT (axis));
+       xlsx_write_chart_uint (xml, "c:axId", 0, xlsx_get_axid (state, axis));
        gsf_xml_out_start_element (xml, "c:scaling");
        xlsx_write_chart_cstr_unchecked (xml, "c:orientation", gog_axis_is_inverted (axis)? "maxMin": 
"minMax");
        // TODO: export min, max, an others
@@ -356,7 +367,7 @@ xlsx_write_axis (XLSXWriteState *state, GsfXMLOut *xml, GogAxis *axis, GogAxisTy
 
        xlsx_write_go_style (xml, go_styled_object_get_style (GO_STYLED_OBJECT (axis)));
 
-       xlsx_write_chart_int (xml, "c:crossAx", 0, GPOINTER_TO_UINT (crossed));
+       xlsx_write_chart_int (xml, "c:crossAx", 0, xlsx_get_axid (state, crossed));
        g_object_get (G_OBJECT (axis), "pos", &pos, NULL);
        switch (pos) {
        default:
@@ -609,7 +620,7 @@ xlsx_write_one_plot (XLSXWriteState *state, GsfXMLOut *xml, GogObject const *cha
        /* write axes Ids */
        for (i = 0; i < 3; i++)
                if (axis_type[i] != GOG_AXIS_UNKNOWN)
-                       xlsx_write_chart_uint (xml, "c:axId", 0, GPOINTER_TO_UINT (gog_plot_get_axis 
(GOG_PLOT (plot), axis_type[i])));
+                       xlsx_write_chart_uint (xml, "c:axId", 0, xlsx_get_axid (state, gog_plot_get_axis 
(GOG_PLOT (plot), axis_type[i])));
 
 
        gsf_xml_out_end_element (xml);
diff --git a/plugins/excel/xlsx-write.c b/plugins/excel/xlsx-write.c
index 3186c81..484addd 100644
--- a/plugins/excel/xlsx-write.c
+++ b/plugins/excel/xlsx-write.c
@@ -97,6 +97,7 @@ static char const *ns_rel_hlink        = "http://schemas.openxmlformats.org/officeDocu
 static char const *ns_rel_draw  = 
"http://schemas.openxmlformats.org/officeDocument/2006/relationships/drawing";;
 static char const *ns_rel_chart         = 
"http://schemas.openxmlformats.org/officeDocument/2006/relationships/chart";;
 static char const *ns_rel_com   = 
"http://schemas.openxmlformats.org/officeDocument/2006/relationships/comments";;
+
 typedef struct {
        XLExportBase base;
 
@@ -111,6 +112,7 @@ typedef struct {
        GPtrArray       *dxfs_array;
        GnmConventions  *convs;
        GOIOContext     *io_context;
+       GHashTable      *axids;
 
        GsfOutfile      *xl_dir;
        struct {
@@ -2917,6 +2919,7 @@ xlsx_write_workbook (XLSXWriteState *state, GsfOutfile *root_part)
        state->styles_array = g_ptr_array_new ();
        state->dxfs_hash = g_hash_table_new (g_direct_hash, g_direct_equal);
        state->dxfs_array = g_ptr_array_new ();
+       state->axids = g_hash_table_new (NULL, NULL);
 
        xlsx_get_style_id (state, style);
        gnm_style_unref (style);
@@ -3014,6 +3017,7 @@ xlsx_write_workbook (XLSXWriteState *state, GsfOutfile *root_part)
        g_ptr_array_free (state->styles_array, TRUE);
        g_hash_table_destroy (state->dxfs_hash);
        g_ptr_array_free (state->dxfs_array, TRUE);
+       g_hash_table_destroy (state->axids);
 
        if (NULL != state->chart.dir)
                gsf_output_close (GSF_OUTPUT (state->chart.dir));