[vala/wip/transform: 75/106] Allow symbol_from_string to return null

[Rico Tzschichholz <ricotz src gnome org>]

commit 7bb3901aae327fb23061528243aece1c4b28b3e1
Author: Luca Bruno <lucabru src gnome org>
Date:   Sun Jun 9 21:22:46 2013 +0200

    Allow symbol_from_string to return null

 vala/valacodebuilder.vala | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/vala/valacodebuilder.vala b/vala/valacodebuilder.vala
index 45f4da490..e2087c7fc 100644
--- a/vala/valacodebuilder.vala
+++ b/vala/valacodebuilder.vala
@@ -265,9 +265,12 @@ public class Vala.CodeBuilder {
        }
 
        // only qualified types, will slightly simplify the work of SymbolResolver
-       public static Symbol symbol_from_string (string symbol_string, Symbol? parent_symbol = null) {
+       public static Symbol? symbol_from_string (string symbol_string, Symbol? parent_symbol = null) {
                Symbol sym = parent_symbol != null ? parent_symbol : CodeContext.get().root;
                foreach (unowned string s in symbol_string.split (".")) {
+                       if (sym == null) {
+                               break;
+                       }
                        sym = sym.scope.lookup (s);
                }
                return sym;