nss_db: fix endent wrt NULL mappings [BZ #24695] [BZ #24696]

nss_db allows for getpwent et al to be called without a set*ent,
but it only works once.  After the last get*ent a set*ent is
required to restart, because the end*ent did not properly reset
the module.  Resetting it to NULL allows for a proper restart.

If the database doesn't exist, however, end*ent erroniously called
munmap which set errno.

The test case runs "makedb" inside the testroot, so needs selinux
DSOs installed.

1 files changed, 17 insertions, 0 deletions

diff --git a/support/links-dso-program.cc b/support/links-dso-program.cc
index dba6976c06..4bc2411086 100644
--- a/support/links-dso-program.cc
+++ b/support/links-dso-program.cc
@@ -1,11 +1,28 @@
 #include <iostream>
 
+/* makedb needs selinux dso's.  */
+#ifdef HAVE_SELINUX
+# include <selinux/selinux.h>
+#endif
+
 using namespace std;
 
+/* The purpose of this file is to indicate to the build system which
+   shared objects need to be copied into the testroot, such as gcc or
+   selinux support libraries.  This program is never executed, only
+   scanned for dependencies on shared objects, so the code below may
+   seem weird - it's written to survive gcc optimization and force
+   such dependencies.
+*/
+
 int
 main (int argc, char **argv)
 {
   /* Complexity to keep gcc from optimizing this away.  */
   cout << (argc > 1 ? argv[1] : "null");
+#ifdef HAVE_SELINUX
+  /* This exists to force libselinux.so to be required.  */
+  cout << "selinux " << is_selinux_enabled ();
+#endif
   return 0;
 }