QQuickStateGroup: Warn if two states have the same name

Otherwise it is silently ignored and given that we change
states by name i think it's a thing the user would want
to know that he made such a mistake, i know i would
since i just lost some time figuring out why changes i made
to a state didn't apply and it was because i had a duplicate
state name in a long states definition

Change-Id: I342e44829f7d32daf6eed0edad33f5b7a42ff5bf
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/quick/util/qquickstategroup.cpp b/src/quick/util/qquickstategroup.cpp
index c852c16509..3d8c5e0507 100644
--- a/src/quick/util/qquickstategroup.cpp
+++ b/src/quick/util/qquickstategroup.cpp
@@ -302,10 +302,18 @@ void QQuickStateGroup::componentComplete()
     Q_D(QQuickStateGroup);
     d->componentComplete = true;
 
+    QSet<QString> names;
     for (int ii = 0; ii < d->states.count(); ++ii) {
         QQuickState *state = d->states.at(ii);
         if (!state->isNamed())
             state->setName(QLatin1String("anonymousState") + QString::number(++d->unnamedCount));
+
+        const QString stateName = state->name();
+        if (names.contains(stateName)) {
+            qmlWarning(state->parent()) << "Found duplicate state name: " << stateName;
+        } else {
+            names << stateName;
+        }
     }
 
     if (d->updateAutoState()) {