Add QgsArcGisRestUtils::convertRectangle

See
https://github.com/qgis/QGIS/pull/54944#pullrequestreview-1680737873

python/core/auto_generated/providers/arcgis/qgsarcgisrestutils.sip.in

@@ -166,6 +166,15 @@ Converts a ``crs`` to an ArcGIS REST JSON representation.
 Returns an empty map if the ``crs`` is not valid.
 
 .. versionadded:: 3.28
+%End
+
+    static QgsRectangle convertRectangle( const QVariant &value );
+%Docstring
+Converts a rectangle ``value`` to a :py:class:`QgsRectangle`.
+
+Returns a null rectangle if the value cannot be converted.
+
+.. versionadded:: 3.34
 %End
 
     enum class FeatureToJsonFlag

src/core/providers/arcgis/qgsarcgisrestquery.cpp

@@ -87,29 +87,7 @@ QgsRectangle QgsArcGisRestQueryUtils::getExtent( const QString &layerurl, const
     return QgsRectangle();
   }
 
-  QgsRectangle rect;
+  return QgsArcGisRestUtils::convertRectangle( res.value( QStringLiteral( "extent" ) ) );
-  do
-  {
-    const QVariantMap coords = res.value( QStringLiteral( "extent" ) ).toMap();
-    if ( coords.isEmpty() ) break;
-    bool ok;
-    const double xmin = coords.value( QStringLiteral( "xmin" ) ).toDouble( &ok );
-    if ( ! ok ) break;
-    const double ymin = coords.value( QStringLiteral( "ymin" ) ).toDouble( &ok );
-    if ( ! ok ) break;
-    const double xmax = coords.value( QStringLiteral( "xmax" ) ).toDouble( &ok );
-    if ( ! ok ) break;
-    const double ymax = coords.value( QStringLiteral( "ymax" ) ).toDouble( &ok );
-    if ( ! ok ) break;
-
-    rect.setXMinimum( xmin );
-    rect.setYMinimum( ymin );
-    rect.setXMaximum( xmax );
-    rect.setYMaximum( ymax );
-  }
-  while ( 0 );
-
-  return rect;
 }
 
 QVariantMap QgsArcGisRestQueryUtils::getObjects( const QString &layerurl, const QString &authcfg, const QList<quint32> &objectIds, const QString &crs,

src/core/providers/arcgis/qgsarcgisrestutils.cpp

@@ -1053,6 +1053,33 @@ QDateTime QgsArcGisRestUtils::convertDateTime( const QVariant &value )
     return dt;
 }
 
+QgsRectangle QgsArcGisRestUtils::convertRectangle( const QVariant &value )
+{
+  if ( QgsVariantUtils::isNull( value ) )
+    return QgsRectangle();
+
+  const QVariantMap coords = value.toMap();
+  if ( coords.isEmpty() ) return QgsRectangle();
+
+  bool ok;
+
+  const double xmin = coords.value( QStringLiteral( "xmin" ) ).toDouble( &ok );
+  if ( ! ok ) return QgsRectangle();
+
+  const double ymin = coords.value( QStringLiteral( "ymin" ) ).toDouble( &ok );
+  if ( ! ok ) return QgsRectangle();
+
+  const double xmax = coords.value( QStringLiteral( "xmax" ) ).toDouble( &ok );
+  if ( ! ok ) return QgsRectangle();
+
+  const double ymax = coords.value( QStringLiteral( "ymax" ) ).toDouble( &ok );
+  if ( ! ok ) return QgsRectangle();
+
+  return QgsRectangle( xmin, ymin, xmax, ymax );
+
+}
+
+
 QVariantMap QgsArcGisRestUtils::geometryToJson( const QgsGeometry &geometry, const QgsArcGisRestContext &, const QgsCoordinateReferenceSystem &crs )
 {
   QVariantMap res;

src/core/providers/arcgis/qgsarcgisrestutils.h

@@ -211,6 +211,15 @@ class CORE_EXPORT QgsArcGisRestUtils
      */
     static QVariantMap crsToJson( const QgsCoordinateReferenceSystem &crs );
 
+    /**
+     * Converts a rectangle \a value to a QgsRectangle.
+     *
+     * Returns a null rectangle if the value cannot be converted.
+     *
+     * \since QGIS 3.34
+     */
+    static QgsRectangle convertRectangle( const QVariant &value );
+
     /**
      * Flags which control the behavior of converting features to JSON.
      *