[vala/0.50] codegen: Don't leak GLib.Value when implicitly unboxing it

[Rico Tzschichholz <ricotz src gnome org>]

commit c9c1ce8f8d38c965d024fc25df68847d46ae0e7e
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Feb 3 13:40:23 2021 +0100

    codegen: Don't leak GLib.Value when implicitly unboxing it
    
    Found by -fsanitize=address

 codegen/valagvaluemodule.vala | 10 ++++++++++
 1 file changed, 10 insertions(+)
---
diff --git a/codegen/valagvaluemodule.vala b/codegen/valagvaluemodule.vala
index a6109fd40..607a8f867 100644
--- a/codegen/valagvaluemodule.vala
+++ b/codegen/valagvaluemodule.vala
@@ -44,6 +44,16 @@ public class Vala.GValueModule : GAsyncModule {
                }
                ccall.add_argument (gvalue);
 
+               if (value_type.is_disposable ()) {
+                       var temp_var = get_temp_variable (value_type, true, expr, false);
+                       emit_temp_var (temp_var);
+                       var temp_ref = get_variable_cexpression (temp_var.name);
+                       ccode.add_assignment (temp_ref, get_cvalue (expr.inner));
+
+                       // value needs to be kept alive until the end of this block
+                       temp_ref_values.insert (0, get_local_cvalue (temp_var));
+               }
+
                CCodeExpression rv = ccall;
 
                if (expr != null && target_type is ArrayType) {