3 files changed, 21 insertions, 13 deletions
diff --git a/src/qml/common/qv4compileddata_p.h b/src/qml/common/qv4compileddata_p.h
index 3db3010885..8641ee3b26 100644
--- a/src/qml/common/qv4compileddata_p.h
+++ b/src/qml/common/qv4compileddata_p.h
@@ -770,6 +770,7 @@ private:
     // object id index (in QQmlContextData::idValues)
     using TargetObjectIdField = quint32_le_bitfield_member<0, 31>;
     using AliasToLocalAliasField = quint32_le_bitfield_member<31, 1>;
+    using IdIndexField = quint32_le_bitfield_member<0, 32>;
 
 public:
 
@@ -781,12 +782,8 @@ public:
     Q_DECLARE_FLAGS(Flags, Flag)
 
     quint32_le_bitfield_union<NameIndexField, FlagsField> nameIndexAndFlags;
-
-    union {
-        quint32_le idIndex; // string index
-        quint32_le_bitfield_union<TargetObjectIdField, AliasToLocalAliasField>
-                targetObjectIdAndAliasToLocalAlias;
-    };
+    quint32_le_bitfield_union<IdIndexField, TargetObjectIdField, AliasToLocalAliasField>
+                idIndexAndTargetObjectIdAndAliasToLocalAlias;
 
     union {
         quint32_le propertyNameIndex; // string index
@@ -827,24 +824,35 @@ public:
         return encodedMetaPropertyIndex == -1;
     }
 
+    quint32 idIndex() const
+    {
+        return idIndexAndTargetObjectIdAndAliasToLocalAlias.get<IdIndexField>();
+    }
+
+    void setIdIndex(quint32 idIndex)
+    {
+        idIndexAndTargetObjectIdAndAliasToLocalAlias.set<IdIndexField>(idIndex);
+    }
+
+
     bool isAliasToLocalAlias() const
     {
-        return targetObjectIdAndAliasToLocalAlias.get<AliasToLocalAliasField>();
+        return idIndexAndTargetObjectIdAndAliasToLocalAlias.get<AliasToLocalAliasField>();
     }
 
     void setIsAliasToLocalAlias(bool isAliasToLocalAlias)
     {
-        targetObjectIdAndAliasToLocalAlias.set<AliasToLocalAliasField>(isAliasToLocalAlias);
+        idIndexAndTargetObjectIdAndAliasToLocalAlias.set<AliasToLocalAliasField>(isAliasToLocalAlias);
     }
 
     quint32 targetObjectId() const
     {
-        return targetObjectIdAndAliasToLocalAlias.get<TargetObjectIdField>();
+        return idIndexAndTargetObjectIdAndAliasToLocalAlias.get<TargetObjectIdField>();
     }
 
     void setTargetObjectId(quint32 targetObjectId)
     {
-        targetObjectIdAndAliasToLocalAlias.set<TargetObjectIdField>(targetObjectId);
+        idIndexAndTargetObjectIdAndAliasToLocalAlias.set<TargetObjectIdField>(targetObjectId);
     }
 };
 static_assert(sizeof(Alias) == 20, "Alias structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index d5bc17735f..213c73d031 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -1301,7 +1301,7 @@ bool IRBuilder::appendAlias(QQmlJS::AST::UiPublicMember *node)
     if (aliasReference.count() < 1 || aliasReference.count() > 3)
         COMPILE_EXCEPTION(rhsLoc, tr("Invalid alias reference. An alias reference must be specified as <id>, <id>.<property> or <id>.<value property>.<property>"));
 
-     alias->idIndex = registerString(aliasReference.first());
+     alias->setIdIndex(registerString(aliasReference.first()));
 
      QString propertyValue = aliasReference.value(1);
      if (aliasReference.count() == 3)
diff --git a/src/qml/qml/qqmltypecompiler.cpp b/src/qml/qml/qqmltypecompiler.cpp
index f45d80e88c..f7a374db28 100644
--- a/src/qml/qml/qqmltypecompiler.cpp
+++ b/src/qml/qml/qqmltypecompiler.cpp
@@ -1071,7 +1071,7 @@ QQmlComponentAndAliasResolver::resolveAliasesInObject(int objectIndex,
 
         seenUnresolvedAlias = true;
 
-        const int idIndex = alias->idIndex;
+        const int idIndex = alias->idIndex();
         const int targetObjectIndex = _idToObjectIndex.value(idIndex, -1);
         if (targetObjectIndex == -1) {
             *error = qQmlCompileError(
@@ -1134,7 +1134,7 @@ QQmlComponentAndAliasResolver::resolveAliasesInObject(int objectIndex,
                     }
 
                     // restore
-                    alias->idIndex = idIndex;
+                    alias->setIdIndex(idIndex);
                     // Try again later and resolve the target alias first.
                     break;
                 }