From 69d96f808107fa18e4d2ee49b058dfa324dae506 Mon Sep 17 00:00:00 2001
From: Francis Deslauriers <francis.deslauriers@efficios.com>
Date: Mon, 30 May 2022 15:55:14 -0400
Subject: [PATCH] Fix: trace-ir.hpp: spurious reference on object creation

We create a variant field class, which initially has refcount == 1.  We
then call `.shared()`, which creates another reference, bringing the
refcount to 2.

Fix that by using the `Shared::createWithoutRef()` method.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: Idfe8184497a00d3192e390017d7717c7ff9a3344
Reviewed-on: https://review.lttng.org/c/babeltrace/+/8187
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/10830
Tested-by: jenkins <jenkins@lttng.org>
CI-Build: Philippe Proulx <eeppeliteloop@gmail.com>
---
 src/cpp-common/bt2/trace-ir.hpp | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/cpp-common/bt2/trace-ir.hpp b/src/cpp-common/bt2/trace-ir.hpp
index 727a9946..a7576a56 100644
--- a/src/cpp-common/bt2/trace-ir.hpp
+++ b/src/cpp-common/bt2/trace-ir.hpp
@@ -2185,17 +2185,15 @@ public:
     VariantWithUnsignedIntegerSelectorFieldClass::Shared
     createVariantWithUnsignedIntegerSelectorFieldClass(const IntegerFieldClass selectorFieldClass)
     {
-        return VariantWithUnsignedIntegerSelectorFieldClass {
-            this->_createVariantWithIntegerSelectorFieldClass(selectorFieldClass)}
-            .shared();
+        return this->_createVariantWithIntegerSelectorFieldClass<
+            VariantWithUnsignedIntegerSelectorFieldClass>(selectorFieldClass);
     }
 
     VariantWithSignedIntegerSelectorFieldClass::Shared
     createVariantWithSignedIntegerSelectorFieldClass(const IntegerFieldClass selectorFieldClass)
     {
-        return VariantWithSignedIntegerSelectorFieldClass {
-            this->_createVariantWithIntegerSelectorFieldClass(selectorFieldClass)}
-            .shared();
+        return this->_createVariantWithIntegerSelectorFieldClass<
+            VariantWithSignedIntegerSelectorFieldClass>(selectorFieldClass);
     }
 
     void assignsAutomaticStreamClassId(const bool val) noexcept
@@ -2273,7 +2271,8 @@ public:
     }
 
 private:
-    bt_field_class *
+    template <typename ObjT>
+    typename ObjT::Shared
     _createVariantWithIntegerSelectorFieldClass(const IntegerFieldClass selectorFieldClass)
     {
         static_assert(!std::is_const<LibObjT>::value, "`LibObjT` must NOT be `const`.");
@@ -2282,7 +2281,7 @@ private:
             bt_field_class_variant_create(this->libObjPtr(), selectorFieldClass.libObjPtr());
 
         internal::validateCreatedObjPtr(libObjPtr);
-        return libObjPtr;
+        return ObjT::Shared::createWithoutRef(libObjPtr);
     }
 };
 
-- 
2.34.1