PVS-Studio warning V534 for Coin3D

cc_xml_elt *
cc_xml_elt_create_x(cc_xml_elt * from, cc_xml_path * path)
{
  ....
  int i;
  for ( i = 0; i < length; i++ ) {
    ....
    int child;
    for (child = 0; i < current->children.getLength(); child++)
    {
  ....
}

This suspicious code was found in Coin3D project by PVS-Studio static code analyzer.
Warning message is:
V534 It is likely that a wrong variable is being compared inside the 'for' operator. Consider reviewing 'i'. element.cpp 996

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/