glib-2.44.1 on OS X 10.8 (clang 5.1):

  CC       keyfile.o
keyfile.c:511:15: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
  const gchar const *list[3];
              ^

Putting "const" before or after "gchar" is equivalent. It looks like the intent was to have a const-pointer to an array of const-strings? That would be:

  const gchar * const list[3];

but that is an *error* because list[] are assigned later:

  list[0] = "one";
  list[1] = "two;andahalf";
  list[2] = "3";

But then they are not changed after that, so the declaration could simply assign the values:

  const gchar * const list[] = {
    "one",
    "two;andahalf",
    "3" };