commit 431afe5167675a89682eb7e07baa3a627ceb8770
Author: Panu Matilainen <pmatilai@redhat.com>
Date:   Fri Jan 28 13:15:09 2011 +0200

    Add an error message + comments on open(".") behavior (RhBug:672576)
    - Bail out early and complain if current directory can't be open()'ed,
      as we'll need it for reliable cwd restoration after running Lua
      scripts.
    - Technically we'd only need open(".") succeeding for chroot operations
      and running Lua-scripts, but there's no easy way to determine whether
      a transaction will run Lua-scripts. They could be in-db triggers
      which will only be evaluated in the middle of transaction, better
      to fail early for consistent behavior.
    (cherry picked from commit fbdfe8e5bf1ef7044de7a14cff9205c4d845f90b)

diff --git a/lib/rpmchroot.c b/lib/rpmchroot.c
index e91be71..81bb5e5 100644
--- a/lib/rpmchroot.c
+++ b/lib/rpmchroot.c
@@ -40,6 +40,7 @@ int rpmChrootSet(const char *rootDir)
 	rootState.rootDir = rstrdup(rootDir);
 	rootState.cwd = open(".", O_RDONLY);
 	if (rootState.cwd < 0) {
+	    rpmlog(RPMLOG_ERR, _("Unable to open current directory: %m\n"));
 	    rc = -1;
 	}
     }
diff --git a/lib/rpmscript.c b/lib/rpmscript.c
index ed52608..3801873 100644
--- a/lib/rpmscript.c
+++ b/lib/rpmscript.c
@@ -55,6 +55,7 @@ static rpmRC runLuaScript(int selinux, ARGV_const_t prefixes,
     rpmluaPop(lua);
 
     /* Lua scripts can change our cwd and umask, save and restore */
+    /* XXX TODO: use cwd from chroot state to save unnecessary open here */
     cwd = open(".", O_RDONLY);
     if (cwd != -1) {
 	int xx;
diff --git a/lib/transaction.c b/lib/transaction.c
index 06e54af..628e4ea 100644
--- a/lib/transaction.c
+++ b/lib/transaction.c
@@ -1260,7 +1260,12 @@ static int rpmtsSetup(rpmts ts, rpmprobFilterFlags ignoreSet)
 	rpmtsSELabelInit(ts, selinux_file_context_path());
     }
 
-    /* XXX Make sure the database is open RDWR for package install/erase. */
+    /* 
+     * Make sure the database is open RDWR for package install/erase.
+     * Note that we initialize chroot state here even if it's just "/" as
+     * this ensures we can successfully perform open(".") which is
+     * required to reliably restore cwd after Lua scripts.
+     */ 
     if (rpmtsOpenDB(ts, dbmode) || rpmChrootSet(rpmtsRootDir(ts)))
 	return -1;