/*
** Return true if the filename given is a valid filename for
** a file in a repository.  Valid filenames follow all of the
** following rules:
**
**     *  Does not begin with "/"
**     *  Does not contain any path element named "." or ".."
**     *  Does not contain any of these characters in the path: "\*[]?"
**     *  Does not end with "/".
**     *  Does not contain two or more "/" characters in a row.
**     *  Contains at least one character
*/
int file_is_simple_pathname(const char *z){
  int i;
  char c = z[0];
  if( c=='/' || c==0 ) return 0;
  if( c=='.' ){
    if( z[1]=='/' || z[1]==0 ) return 0;
    if( z[1]=='.' && (z[2]=='/' || z[2]==0) ) return 0;
  }
  for(i=0; (c=z[i])!=0; i++){
    if( c=='\\' || c=='*' || c=='[' || c==']' || c=='?' ){
      return 0;
    }
    if( c=='/' ){
      if( z[i+1]=='/' ) return 0;
      if( z[i+1]=='.' ){
        if( z[i+2]=='/' || z[i+2]==0 ) return 0;
        if( z[i+2]=='.' && (z[i+3]=='/' || z[i+3]==0) ) return 0;