[vala/0.54] vala: Free empty stack list for code contexts

[Rico Tzschichholz <ricotz src gnome org>]

commit 2f67004de39fe6028c461bb953651b20c7f9a418
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Feb 9 17:36:14 2022 +0100

    vala: Free empty stack list for code contexts
    
    While having the stack list created on demand, make sure to destroy it
    when it is not required anymore. Otherwise it will be leaked without an
    option to avoid that to happen.

 vala/valacodecontext.vala | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/vala/valacodecontext.vala b/vala/valacodecontext.vala
index 9fc211f7a..f96f87911 100644
--- a/vala/valacodecontext.vala
+++ b/vala/valacodecontext.vala
@@ -286,6 +286,11 @@ public class Vala.CodeContext {
                }
 
                context_stack->remove_at (context_stack->size - 1);
+
+               if (context_stack->size == 0) {
+                       delete context_stack;
+                       context_stack_key.set (null, null);
+               }
        }
 
        /**