[gnumeric] export transparent patterns to xls as no filling.

[Jean Bréfort <jbrefort src gnome org>]

commit 3aa82ac27ddcbf44c139a704f030b26ce8f5c419
Author: Jean Brefort <jean brefort normalesup org>
Date:   Wed Mar 31 16:50:18 2010 +0200

    export transparent patterns to xls as no filling.

 plugins/excel/ChangeLog  |    5 +++++
 plugins/excel/ms-chart.c |   23 +++++++++++++++--------
 2 files changed, 20 insertions(+), 8 deletions(-)
---
diff --git a/plugins/excel/ChangeLog b/plugins/excel/ChangeLog
index de3f292..a85659a 100644
--- a/plugins/excel/ChangeLog
+++ b/plugins/excel/ChangeLog
@@ -1,3 +1,8 @@
+2010-03-31  Jean Brefort  <jean brefort normalesup org>
+
+	* ms-chart.c (chart_write_AREAFORMAT): export transparent patterns as
+	no filling.
+
 2010-03-29  Morten Welinder  <terra gnome org>
 
 	* ms-formula-write.c (write_funcall): Guess argument types for
diff --git a/plugins/excel/ms-chart.c b/plugins/excel/ms-chart.c
index a63fb39..213008a 100644
--- a/plugins/excel/ms-chart.c
+++ b/plugins/excel/ms-chart.c
@@ -3952,17 +3952,24 @@ chart_write_AREAFORMAT (XLChartWriteState *s, GOStyle const *style, gboolean dis
 			fore = GO_COLOR_WHITE;
 			back = GO_COLOR_WHITE;
 			break;
-		case GO_STYLE_FILL_PATTERN: {
-			pat = style->fill.pattern.pattern + 1;
-			if (pat == 1) {
-				back = style->fill.pattern.fore;
-				fore = style->fill.pattern.back;
+		case GO_STYLE_FILL_PATTERN:
+			if ((style->fill.pattern.pattern == GO_PATTERN_SOLID && style->fill.pattern.back == 0)
+			    || (style->fill.pattern.pattern == GO_PATTERN_FOREGROUND_SOLID && style->fill.pattern.fore == 0)
+			    || (style->fill.pattern.fore == 0 && style->fill.pattern.back == 0)) {
+				pat = 0;
+				fore = GO_COLOR_WHITE;
+				back = GO_COLOR_WHITE;
 			} else {
-				fore = style->fill.pattern.fore;
-				back = style->fill.pattern.back;
+				pat = style->fill.pattern.pattern + 1;
+				if (pat == 1) {
+					back = style->fill.pattern.fore;
+					fore = style->fill.pattern.back;
+				} else {
+					fore = style->fill.pattern.fore;
+					back = style->fill.pattern.back;
+				}
 			}
 			break;
-		}
 		case GO_STYLE_FILL_GRADIENT:
 			pat = 1;
 			fore = back = style->fill.pattern.fore;