PVS-Studio warning V547 for UltimateTCPIP

void CUT_StrMethods::RemoveSpaces(LPSTR szString) {
  ...
  size_t loop, len = strlen(szString);
  // Remove the trailing spaces
  for(loop = (len-1); loop >= 0; loop--) {
    if(szString[loop] != ' ')
      break;
  }
  ...
}

An example of vulnerability. If a string contains only blanks, an array overrun will occur.


This suspicious code was found in UltimateTCPIP project by PVS-Studio static code analyzer.
Warning message is:
V547 Expression 'loop >= 0' is always true. Unsigned type value is always >= 0. UTDns utstrlst.cpp 430

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/