Suppress (GitHub CI/wayland) compiler warning

[ 15%] Building CXX object src/CMakeFiles/fltk.dir/Fl_Text_Display.cxx.o
.../fltk/src/Fl_Text_Display.cxx: In constructor ‘Fl_Text_Display::Fl_Text_Display(int, int, int, int, const char*)’:
.../fltk/src/Fl_Text_Display.cxx:122:57: warning: ‘void* __builtin_memset(void*, int, long unsigned int)’ writing between 4 and 8589934584 bytes into a region of size 0 overflows the destination [-Wstringop-overflow=]
  122 |     for (int i=1; i<mNVisibleLines; i++) mLineStarts[i] = -1;
      |                                          ~~~~~~~~~~~~~~~^~~~
.../fltk/src/Fl_Text_Display.cxx:120:39: note: at offset 4 into destination object of size 4 allocated by ‘operator new []’
  120 |   mLineStarts = new int[mNVisibleLines];
      |                                       ^

This warning is IMHO obsolete because the code in question should not
be executed at all (mNVisibleLines == 1). However, the compiler seems
to substitute this with '__builtin_memset(...)' and analyzes "correctly"
that memory at offset 4 would be overwritten but not that the written
size would be 0.

The "fix" uses a compiler macro and #if to clarify that this code must
not be executed and should not be compiled (see comment why this code
exists).

0 files changed, 0 insertions, 0 deletions