[vala] valac: Require --header when using --use-header

[Jürg Billeter <juergbi src gnome org>]

commit 3c53cbc399b95be3dc274b095d11c53267a7e2dd
Author: Jürg Billeter <j bitron ch>
Date:   Sun Dec 6 18:25:00 2009 +0100

    valac: Require --header when using --use-header

 compiler/valacompiler.vala |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/compiler/valacompiler.vala b/compiler/valacompiler.vala
index 11c35fc..3f37fbd 100644
--- a/compiler/valacompiler.vala
+++ b/compiler/valacompiler.vala
@@ -213,6 +213,9 @@ class Vala.Compiler {
 		context.ccode_only = ccode_only;
 		context.compile_only = compile_only;
 		context.header_filename = header_filename;
+		if (header_filename == null && use_header) {
+			Report.error (null, "--use-header may only be used in combination with --header");
+		}
 		context.use_header = use_header;
 		context.internal_header_filename = internal_header_filename;
 		context.includedir = includedir;