[Interest] QStringBuilder buffer overflow with string litteral?

[Olivier B.]

Compiling with QT 5.11.1 &  QT_USE_QSTRINGBUILDER, i get an error with the
following code block:

  QString generateQuery(const QString& tableName, const QStringList&
columns, int count)
  {
    QString fields = "*";
    if (!columns.isEmpty())
    {
      fields.clear();
      for (const QString& field : columns)
      {
        fields += (fields.isEmpty() ? "" : ", ") + '"' + field + '"';
      }
    }
...

I just want to build a comma separated list of the items in 'columns',
surrounded by quotes.
But instead of giving "A", "B", "C", this gives UNIQUE (%1)"A"UNIQUE
(%1)"B"UNIQUE (%1)"C"

That UNIQUE (%1) is only found in another cpp file of the same DLL project,
in strings ", UNIQUE (%1)" passed to QString constructors. So not only is
it using the wrong string litteral, it does not read it from the string
start.

Passing one/both of the operands of the ternary operator as QStrings makes
the problem disappear.

Are there things i should be aware of when using QStringBuilder, such as
'do not put expressions on operators, because of macros that will evaluate
them multiple times', or something like that?
String pooling (/GF of visual studio) is not used, if that matters
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