[gnumeric] Rich text: fix display issue with newer Pangos.

[Morten Welinder <mortenw src gnome org>]

commit 1b39e8c96e77d97d3dd9fd9fadf19b0a7aa55077
Author: Morten Welinder <terra gnome org>
Date:   Sun Jan 9 12:43:24 2022 -0500

    Rich text: fix display issue with newer Pangos.
    
    See #607.

 ChangeLog            | 7 +++++++
 NEWS                 | 1 +
 src/rendered-value.c | 3 ++-
 3 files changed, 10 insertions(+), 1 deletion(-)
---
diff --git a/ChangeLog b/ChangeLog
index 1cfd27f50..b99968edd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2022-01-09  Morten Welinder  <terra gnome org>
+
+       * src/rendered-value.c (gnm_rendered_value_new): Work around Pango
+       bug 653, see Gnumeric bug 607.  Pango is fixing the issue, but we
+       need to deal with the situation.  In the long run, something based
+       on pango_attr_list_change should probably be used.
+
 2021-12-26  Morten Welinder  <terra gnome org>
 
        * src/xml-sax-read.c (xml_cell_set_array_expr): Take position as
diff --git a/NEWS b/NEWS
index d33c3f3ac..c3d9a9cdb 100644
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,7 @@ Morten:
        * Take evasive action re g_memdup.
        * Fix inter-gnumeric array formula paste crash.  [#606]
        * Avoid re-querying file existance for recent files.  [Part of #602]
+       * Fix rich-text rendering (based on work of Jean).  [#607]
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.50
diff --git a/src/rendered-value.c b/src/rendered-value.c
index 664afbf62..a5d5cc1ff 100644
--- a/src/rendered-value.c
+++ b/src/rendered-value.c
@@ -395,7 +395,8 @@ gnm_rendered_value_new (GnmCell const *cell,
                                rv_adjust_attributes (c_markup, zoom, tscale, rise);
                        }
 
-                       pango_attr_list_splice (attrs, (PangoAttrList *)markup, 0, 0);
+                       // See #607
+                       pango_attr_list_splice (attrs, (PangoAttrList *)markup, 0, INT_MAX / 2);
                        pango_attr_list_unref (orig);
                        pango_attr_list_unref (c_markup);
                }