[atk] Provide ability to get character attributes at "insertion point".

[Li Yuan <liyuan src gnome org>]

commit 2437df0d1ba6dcc6962d2c75f50b46f7015e00b8
Author: Li Yuan <li yuan sun com>
Date:   Wed Jun 3 17:44:35 2009 +0800

    Provide ability to get character attributes at "insertion point".
    
    Bug #489828.
---
 atk/atktext.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/atk/atktext.c b/atk/atktext.c
index 10a80ee..5bb9397 100755
--- a/atk/atktext.c
+++ b/atk/atktext.c
@@ -599,7 +599,8 @@ atk_text_get_character_extents (AtkText *text,
 /**
  *atk_text_get_run_attributes:
  * text: an #AtkText
- * offset: the offset at which to get the attributes
+ * offset: the offset at which to get the attributes, -1 means the offset of
+ *the character to be inserted at the caret location.
  * start_offset: the address to put the start offset of the range
  * end_offset: the address to put the end offset of the range
  *
@@ -636,7 +637,7 @@ atk_text_get_run_attributes (AtkText          *text,
   else
     real_end_offset = &local_end_offset;
 
-  if (offset < 0)
+  if (offset < -1)
     return NULL;
 
   iface = ATK_TEXT_GET_IFACE (text);