Bug 245189

Description of problem:

slocate replaces an existing slocate database with an empty file before creating
a new database

Version-Release number of selected component (if applicable):

2.7-13.el4.6

How reproducible:

Every time

Steps to Reproduce:
1. Run slocate -u
2.
3.
  
Actual results:

Any existing database is replaced with a zero length file while a new database
is being built with a temporary (different) name

Expected results:

Replace existing database with the new one after the new database has been built

Additional info:

On a (very) large filesystem, it might take a while to re-generate an slocate
database - while the new database is being created, searches on the database
fail as the database is empty.

From the source, the first thing it does is:

    ret_val = creat(path, S_IRWXU|S_IRGRP);
    if(ret_val==-1)
        report_error(FATAL,QUIET,"%s: parse_create_path: could not create
database: %s: %s\n", progname,path,strerror(errno));

i.e. the creat() creates a new empty database file (truncates any existing file)

It then goes on to build a new database using a temporary file name - once it
has finished, it replaces this empty file with the new database.

As the creat() is only used to check that the database file can be created,
there are other ways to check this without trashing the existing file - e.g.
something like:

    ret_val = open(path, O_WRONLY|O_CREAT, S_IRWXU|S_IRGRP);
    if(ret_val==-1)
       report_error(...);
    else
       close(ret_val);