[ATSUI] Prevent segfault in _cairo_atsuii_font_text_to_glyphs (bug 5177)

---
commit c9cc2f95179576bf78fb81ccc8067c30c000cdff
tree 3bce551a75efe455d807e4e14cd33624d92a8e37
parent 7bc6ad3f956c5ba6c98c26fcf641c0855b65f7ba
author Brian Ewins <Brian.Ewins@gmail.com> Fri, 22 Dec 2006 00:31:14 +0000
committer Brian Ewins <Brian.Ewins@gmail.com> Fri, 22 Dec 2006 00:31:14 +0000

 src/cairo-atsui-font.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/src/cairo-atsui-font.c b/src/cairo-atsui-font.c
index edaa061..e6e20eb 100644
--- a/src/cairo-atsui-font.c
+++ b/src/cairo-atsui-font.c
@@ -651,6 +651,12 @@ _cairo_atsui_font_text_to_glyphs (void
     if (status)
 	return status;
 
+    if (n16 == 0) {
+	*num_glyphs = 0;
+	*glyphs = NULL;
+	return noErr;
+    }
+
     err = ATSUCreateTextLayout(&textLayout);
 
     err = ATSUSetTextPointerLocation(textLayout, utf16, 0, n16, n16);