[gnumeric] GUI: Fix crash when selecting invalid dates.

[Morten Welinder <mortenw src gnome org>]

commit 46bf2d7e2bbc1053b1e4bded406305fc259a95fa
Author: Morten Welinder <terra gnome org>
Date:   Mon Sep 26 14:55:45 2011 -0400

    GUI: Fix crash when selecting invalid dates.

 ChangeLog        |    2 ++
 NEWS             |    1 +
 src/gnm-format.c |   19 ++++++++++++++-----
 3 files changed, 17 insertions(+), 5 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index f9684b4..8f044ca 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2011-09-26  Morten Welinder  <terra gnome org>
 
+	* src/gnm-format.c (hash_fill): Handle NULL str without crash.
+
 	* src/wbc-gtk-actions.c (cb_add_component_from_file): #if 0.
 
 	* src/main-application.c (call_gnome_authentication_manager_init):
diff --git a/NEWS b/NEWS
index cdccd91..10883c1 100644
--- a/NEWS
+++ b/NEWS
@@ -38,6 +38,7 @@ Morten:
 	* Fix crash.  [#658140]
 	* Fix stf import crash.  [#658982]
 	* Fix leaks.
+	* Fix GUI crash for invalid dates.
 
 Valek:
 	* In xls import, set LABEL encoding based on FONT charset converted to 
diff --git a/src/gnm-format.c b/src/gnm-format.c
index 1647941..e6dcd72 100644
--- a/src/gnm-format.c
+++ b/src/gnm-format.c
@@ -65,16 +65,25 @@ static void
 hash_fill (PangoLayout *layout, GString *str, const GOFontMetrics *metrics, int col_width)
 {
 	if (col_width <= 0) {
-		g_string_truncate (str, 0);
-		if (layout) pango_layout_set_text (layout, str->str, -1);
+		if (str) g_string_truncate (str, 0);
+		if (layout) pango_layout_set_text (layout, "", -1);
 	} else {
 		int l = metrics->hash_width > 0
 			? col_width / metrics->hash_width
 			: 1;
-		g_string_set_size (str, l);
-		memset (str->str, '#', str->len);
+		GString *hashstr;
+
+		if (str) {
+			hashstr = str;
+			g_string_truncate (hashstr, 0);
+		} else {
+			hashstr = g_string_sized_new (l);
+		}
+		go_string_append_c_n (hashstr, '#', l);
 		if (layout)
-			pango_layout_set_text (layout, str->str, -1);
+			pango_layout_set_text (layout, hashstr->str, -1);
+		if (str != hashstr)
+			g_string_free (hashstr, TRUE);
 	}
 }