PVS-Studio warning V519 for QT

static BOOL
compile_branch(....)
{
  ....
  pcre_uint32 firstchar;
  ....
  firstchar = mcbuffer[0] | req_caseopt;
  firstchar = mcbuffer[0];
  ....
}

This suspicious code was found in QT project by PVS-Studio static code analyzer.
Warning message is:
V519 The 'firstchar' variable is assigned values twice successively. Perhaps this is a mistake. Check lines: 7018, 7019. pcre_compile.c 7019

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/