[vala/0.46] vala: Do not allow to change .length of arrays with fixed length

[Rico Tzschichholz <ricotz src gnome org>]

commit efb5479f7033d91b3d82e8d6c7636db33d848cfd
Author: Florian Brosch <flo brosch gmail com>
Date:   Wed Sep 17 14:45:52 2014 +0200

    vala: Do not allow to change .length of arrays with fixed length
    
    This would result in invalid C code.

 tests/arrays/fixed-length-read-only-length.test | 6 ++++++
 vala/valaassignment.vala                        | 4 ++++
 2 files changed, 10 insertions(+)
---
diff --git a/tests/arrays/fixed-length-read-only-length.test b/tests/arrays/fixed-length-read-only-length.test
new file mode 100644
index 000000000..b53eb112a
--- /dev/null
+++ b/tests/arrays/fixed-length-read-only-length.test
@@ -0,0 +1,6 @@
+Invalid Code
+
+void main () {
+       int foo[2] = { 23, 42 };
+       foo.length = 3;
+}
diff --git a/vala/valaassignment.vala b/vala/valaassignment.vala
index 9db0ec163..0920a48fb 100644
--- a/vala/valaassignment.vala
+++ b/vala/valaassignment.vala
@@ -290,6 +290,10 @@ public class Vala.Assignment : Expression {
                                                return false;
                                        }
                                }
+                       } else if (ma.symbol_reference is ArrayLengthField && ((ArrayType) 
ma.inner.value_type).inline_allocated) {
+                               error = true;
+                               Report.error (source_reference, "`length' field of fixed length arrays is 
read-only");
+                               return false;
                        } else if (ma.symbol_reference is Variable && right.value_type == null) {
                                var variable = (Variable) ma.symbol_reference;