[omnibus] Don't create RPM database if it doesn't exist already (#17398)

On Linux distributions not using the RPM package manager
(Debian, Ubuntu, etc.), the rpm probe of OpenSCAP could
initialize the sqlite RPM database into the /var/lib/rpm,
directory, as a side effect.

This change adds a new patch "rpmdb-no-create" to the RPM package.

This patch changes the openDatabase function to prevent creation
of the RPM database when it doesn't exist already.

omnibus/config/patches/rpm/rpmdb-no-create.patch

@@ -0,0 +1,25 @@
+--- a/lib/rpmdb.c
++++ b/lib/rpmdb.c
+@@ -463,6 +463,11 @@ static int openDatabase(const char * prefix,
+     if (db == NULL)
+ 	return 1;
+
++    /* Don't create db if it doesn't exist already */
++    struct stat st;
++    if (stat(rpmdbHome(db), &st) < 0)
++        return 1;
++
+     /* Try to ensure db home exists, error out if we can't even create */
+     rc = rpmioMkpath(rpmdbHome(db), 0755, getuid(), getgid());
+     if (rc == 0) {
+--- a/lib/rpmts.c
++++ b/lib/rpmts.c
+@@ -104,7 +104,7 @@ int rpmtsOpenDB(rpmts ts, int dbmode)
+     rc = rpmdbOpen(ts->rootDir, &ts->rdb, ts->dbmode, 0644);
+     if (rc) {
+ 	char * dn = rpmGetPath(ts->rootDir, "%{_dbpath}", NULL);
+-	rpmlog(RPMLOG_ERR, _("cannot open Packages database in %s\n"), dn);
++	rpmlog(RPMLOG_DEBUG, _("cannot open Packages database in %s\n"), dn);
+ 	free(dn);
+     }
+     return rc;

omnibus/config/software/rpm.rb

@@ -49,6 +49,7 @@
   env["CFLAGS"] << " -fPIC"
 
   patch source: "0001-Include-fcntl.patch", env: env # fix build
+  patch source: "rpmdb-no-create.patch", env: env # don't create db if it doesn't exist already
 
   update_config_guess