[librsvg] Workaround for bug #581491.

[Hiroyuki Ikezoe <hiikezoe src gnome org>]

commit a8f93e33ac216dd8eb559a4d8967d099af916b94
Author: Hiroyuki Ikezoe <poincare ikezoe net>
Date:   Fri Apr 16 19:40:54 2010 +0900

    Workaround for bug #581491.

 rsvg-text.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/rsvg-text.c b/rsvg-text.c
index f0d0496..5e539a1 100644
--- a/rsvg-text.c
+++ b/rsvg-text.c
@@ -929,6 +929,11 @@ rsvg_text_render_text (RsvgDrawingCtx * ctx, const char *text, gdouble * x, gdou
         gint w, h, baseline;
 
         state = rsvg_state_current (ctx);
+
+	/* Do not render the text if the font size is zero. See bug #581491. */
+	if (state->font_size.length == 0)
+	    return;
+
         context = ctx->render->create_pango_context (ctx);
         layout = rsvg_text_create_layout (ctx, state, text, context);
         pango_layout_get_size (layout, &w, &h);