[valadoc] libvaladoc: gtkdoc-parser: Fix possible segfault in footnotes

[Florian Brosch <flobrosch src gnome org>]

commit fcc844f91e153ef9270c7f913c32ab78d57841d0
Author: Florian Brosch <flo brosch gmail com>
Date:   Mon Jan 16 01:05:37 2012 +0100

    libvaladoc: gtkdoc-parser: Fix possible segfault in footnotes

 .../documentation/gtkdoccommentparser.vala         |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/libvaladoc/documentation/gtkdoccommentparser.vala b/src/libvaladoc/documentation/gtkdoccommentparser.vala
index ec1ced6..574e65f 100644
--- a/src/libvaladoc/documentation/gtkdoccommentparser.vala
+++ b/src/libvaladoc/documentation/gtkdoccommentparser.vala
@@ -947,7 +947,7 @@ public class Valadoc.Gtkdoc.Parser : Object, ResourceLocator {
 			}
 		}
 
-		Paragraph first = content.first () as Paragraph;
+		Paragraph? first = (content.is_empty)? null : content.first () as Paragraph;
 		if (first == null) {
 			first = factory.create_paragraph ();
 			content.insert (0, first);