[gnumeric] Write the null date in OOXML export.

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

commit efb4fec899c568aef80b52033804c5a8f66d011f
Author: Andreas J. Guelzow <aguelzow pyrshep ca>
Date:   Wed Apr 14 23:00:14 2010 -0600

    Write the null date in OOXML export.
    
    2010-04-14  Andreas J. Guelzow <aguelzow pyrshep ca>
    
    	* xlsx-write.c (xlsx_write_workbook): write 1900/1904 date
    	  base info

 NEWS                       |    1 +
 plugins/excel/ChangeLog    |    5 +++++
 plugins/excel/xlsx-write.c |    6 +++++-
 3 files changed, 11 insertions(+), 1 deletions(-)
---
diff --git a/NEWS b/NEWS
index 7b0531f..b4b3733 100644
--- a/NEWS
+++ b/NEWS
@@ -17,6 +17,7 @@ Andreas:
 	* Adjust regression tool to reflect the changes to TDIST.
 	* Basic import and export of text boxes from ODF files.
 	* Watch for the null date in OOXML import. [#615777]
+	* Write the null date in OOXML export.
 
 Jean:
 	* Print pattern backgrounds. [#615365]
diff --git a/plugins/excel/ChangeLog b/plugins/excel/ChangeLog
index c132a79..693fa67 100644
--- a/plugins/excel/ChangeLog
+++ b/plugins/excel/ChangeLog
@@ -1,5 +1,10 @@
 2010-04-14  Andreas J. Guelzow <aguelzow pyrshep ca>
 
+	* xlsx-write.c (xlsx_write_workbook): write 1900/1904 date 
+	  base info
+	
+2010-04-14  Andreas J. Guelzow <aguelzow pyrshep ca>
+
 	* xlsx-read.c (xlsx_CT_WorkbookPr): new
 	(xlsx_workbook_dtd); hook up xlsx_CT_WorkbookPr
 
diff --git a/plugins/excel/xlsx-write.c b/plugins/excel/xlsx-write.c
index d1ccdad..f6b371c 100644
--- a/plugins/excel/xlsx-write.c
+++ b/plugins/excel/xlsx-write.c
@@ -1431,7 +1431,11 @@ xlsx_write_workbook (XLSXWriteState *state, GsfOutfile *root_part)
 	gsf_xml_out_add_int (xml, "rupBuild", 3820);
 	gsf_xml_out_end_element (xml);
 
-	gsf_xml_out_simple_element (xml, "workbookPr", NULL);
+	gsf_xml_out_start_element (xml, "workbookPr");
+	gsf_xml_out_add_int (xml, "date1904", 
+			     workbook_date_conv (state->base.wb)->use_1904 
+			     ? 1 : 0);
+	gsf_xml_out_end_element (xml);
 
 	gsf_xml_out_start_element (xml, "bookViews");
 	WORKBOOK_FOREACH_VIEW (state->base.wb, view, {