[gnumeric] xls: fix crash on save.

[Morten Welinder <mortenw src gnome org>]

commit 092fe3811b2c4819d82b2fd80c59cc47f2aead6b
Author: Morten Welinder <terra gnome org>
Date:   Tue Mar 6 19:28:25 2012 -0500

    xls: fix crash on save.

 NEWS                           |    1 +
 plugins/excel/ChangeLog        |    7 +++++++
 plugins/excel/ms-excel-write.c |    9 +++++----
 3 files changed, 13 insertions(+), 4 deletions(-)
---
diff --git a/NEWS b/NEWS
index 6c6e081..ce64aa6 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,7 @@ Andreas:
 
 Morten:
 	* Hook up unknown_image icon for ssconvert too.
+	* Fix xls save crash.  [#671267]
 
 --------------------------------------------------------------------------
 Gnumeric 1.11.2
diff --git a/plugins/excel/ChangeLog b/plugins/excel/ChangeLog
index 5e79a76..fe35907 100644
--- a/plugins/excel/ChangeLog
+++ b/plugins/excel/ChangeLog
@@ -1,3 +1,10 @@
+2012-03-06  Morten Welinder  <terra gnome org>
+
+	* ms-excel-write.c (cb_write_condition): Handle lack of style
+	conditions.
+	(excel_write_prep_conditions): Ditto.
+	(put_colors): Ditto.  Fixes crash of #671267.
+
 2012-03-02  Morten Welinder <terra gnome org>
 
 	* Release 1.11.2
diff --git a/plugins/excel/ms-excel-write.c b/plugins/excel/ms-excel-write.c
index e209c7b..91618fa 100644
--- a/plugins/excel/ms-excel-write.c
+++ b/plugins/excel/ms-excel-write.c
@@ -930,12 +930,13 @@ cb_write_condition (GnmStyleConditions const *sc, CondDetails *cd,
 	guint32 flags = 0x38C3FF;	/* these are always true */
 	unsigned i, expr0_len, expr1_len, header_pos;
 	GArray const *details = gnm_style_conditions_details (sc);
+	unsigned det_len = details ? details->len : 0;
 	GnmStyleCond const *cond;
 	GnmStyle const *s;
 
 	/* The parent record */
 	ms_biff_put_var_next (bp, BIFF_CONDFMT);
-	GSF_LE_SET_GUINT16 (buf+0, details->len);
+	GSF_LE_SET_GUINT16 (buf+0, det_len);
 	GSF_LE_SET_GUINT16 (buf+2, 1); /* force a redraw */
 	xl_le_set_range (buf+4, &cd->bb);
 	range_count = g_slist_length (cd->ranges);
@@ -949,7 +950,7 @@ cb_write_condition (GnmStyleConditions const *sc, CondDetails *cd,
 	g_slist_free (cd->ranges);
 
 	/* The individual conditions */
-	for (i = 0 ; i < details->len ; i++) {
+	for (i = 0 ; i < det_len ; i++) {
 		cond = &g_array_index (details, GnmStyleCond, i);
 		s = cond->overlay;
 
@@ -1494,7 +1495,7 @@ excel_write_prep_conditions (ExcelWriteSheet *esheet)
 			continue;
 		conds = gnm_style_conditions_details (
 			gnm_style_get_conditions (sr->style));
-		for (i = 0 ; i < conds->len ; i++) {
+		for (i = 0 ; i < (conds ? conds->len : 0) ; i++) {
 			cond = &g_array_index (conds, GnmStyleCond, i);
 			if (cond->texpr[0] != NULL)
 				excel_write_prep_expr (esheet->ewb, cond->texpr[0]);
@@ -1801,7 +1802,7 @@ put_colors (ExcelStyleVariant const *esv, gpointer dummy, XLExportBase *ewb)
 	    NULL != gnm_style_get_conditions (st)) {
 		GArray const *conds = gnm_style_conditions_details (
 			gnm_style_get_conditions (st));
-		for (i = 0 ; i < conds->len ; i++) {
+		for (i = 0 ; i < (conds ? conds->len : 0) ; i++) {
 			st = g_array_index (conds, GnmStyleCond, i).overlay;
 			if (gnm_style_is_element_set (st, MSTYLE_FONT_COLOR))
 				put_color_gnm (ewb, gnm_style_get_font_color (st));