Cdbext: Fix fetching partial variable

Avoid calling PyValue::childCount as it expands the values in front of the
partial variable recursively. This outdates scopeEnd as it is fetched
before the items are expanded, which again results in a too early return
from that function.

Fixes: QTCREATORBUG-24108
Change-Id: I0848cde88c6ff8019a4ab22ac1153598c20e563d
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/libs/qtcreatorcdbext/pycdbextmodule.cpp

@@ -220,17 +220,13 @@ static PyObject *cdbext_listOfLocals(PyObject *, PyObject *args) // -> [ Value ]
         ++currentPartialIname; // skip "local" part
 
         ULONG symbolGroupIndex = 0;
-        ULONG childEndIndex = 0;
         for (;symbolGroupIndex < scopeEnd; ++symbolGroupIndex) {
             PyValue value(symbolGroupIndex, symbolGroup);
-            if (childEndIndex <= symbolGroupIndex) { // do not return a child value
+            if (value.name() == *currentPartialIname) {
-                if (value.name() == *currentPartialIname) {
+                PyList_Append(locals, createPythonObject(value));
-                    PyList_Append(locals, createPythonObject(value));
+                return locals;
-                    return locals;
-                }
-                ++childEndIndex;
             }
-            childEndIndex += ULONG(value.childCount());
+            symbolGroupIndex += value.currentNumberOfDescendants();
         }
     }
 

src/libs/qtcreatorcdbext/pyvalue.cpp

@@ -278,13 +278,18 @@ PyValue PyValue::childFromIndex(int index)
 
     int offset = index + 1;
     for (ULONG childIndex = m_index + 1; childIndex < m_index + offset; ) {
-        const ULONG childDescendantCount = currentNumberOfDescendants(childIndex, m_symbolGroup);
+        const ULONG childDescendantCount = ::currentNumberOfDescendants(childIndex, m_symbolGroup);
         childIndex += childDescendantCount + 1;
         offset += childDescendantCount;
     }
     return PyValue(m_index + offset, m_symbolGroup);
 }
 
+ULONG PyValue::currentNumberOfDescendants()
+{
+    return ::currentNumberOfDescendants(m_index, m_symbolGroup);
+}
+
 PyValue PyValue::createValue(ULONG64 address, const PyType &type)
 {
     if (debuggingValueEnabled()) {

src/libs/qtcreatorcdbext/pyvalue.h

@@ -55,6 +55,7 @@ public:
     PyValue childFromName(const std::string &name);
     PyValue childFromField(const PyField &field);
     PyValue childFromIndex(int index);
+    ULONG currentNumberOfDescendants();
 
     static PyValue createValue(ULONG64 address, const PyType &type);
     static int tag(const std::string &typeName);