Merge topic '18127-python-trace-has-duplicate-entries'

c13bc362 fixes duplicate trace items in Python traces.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Mathieu Westphal <mathieu.westphal@kitware.com>
Merge-request: !2944

Qt/Components/pqProxySelectionWidget.cxx

@@ -38,6 +38,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "vtkPVXMLElement.h"
 #include "vtkSMProperty.h"
 #include "vtkSMProxyListDomain.h"
+#include "vtkSMTrace.h"
 #include "vtkSmartPointer.h"
 #include "vtkWeakPointer.h"
 
@@ -187,11 +188,14 @@ void pqProxySelectionWidget::currentIndexChanged(int idx)
 //-----------------------------------------------------------------------------
 void pqProxySelectionWidget::apply()
 {
-  if (this->Internal->ProxyWidget)
+  this->Superclass::apply();
+  if (auto nestedWidget = this->Internal->ProxyWidget)
   {
-    this->Internal->ProxyWidget->apply();
+    // we need to block tracing since the "nested proxy" will indeed get traced
+    // by the parent proxy. See #18127.
+    SM_SCOPED_TRACE(BlockTraceItems);
+    nestedWidget->apply();
   }
-  this->Superclass::apply();
 }
 
 //-----------------------------------------------------------------------------

Wrapping/Python/paraview/smtrace.py

@@ -902,6 +902,14 @@ class CleanupAccessor(BookkeepingItem):
         import gc
         gc.collect()
 
+class BlockTraceItems(NestableTraceItem):
+    """Item to block further creation of trace items, even
+    those that are `NestableTraceItem`. Simply create this and
+    no trace items will be created by `_create_trace_item_internal`
+    until this instance is cleaned up.
+    """
+    pass
+
 class PropertiesModified(NestableTraceItem):
     """Traces properties modified on a specific proxy."""
     def __init__(self, proxy, comment=None):
@@ -1488,7 +1496,11 @@ def _create_trace_item_internal(key, args=None, kwargs=None):
         args = args if args else []
         kwargs = kwargs if kwargs else {}
         traceitemtype = g[key]
-        if len(__ActiveTraceItems) == 0 or issubclass(traceitemtype, NestableTraceItem):
+        if len(__ActiveTraceItems) == 0 or \
+                issubclass(traceitemtype, NestableTraceItem):
+            if len(__ActiveTraceItems) > 0 and \
+                    isinstance(__ActiveTraceItems[-1](), BlockTraceItems):
+                raise Untraceable("Not tracing since `BlockTraceItems` is active.")
             instance = traceitemtype(*args, **kwargs)
             if not issubclass(traceitemtype, BookkeepingItem):
                 __ActiveTraceItems.append(weakref.ref(instance))