pkg/42213: pkg_install-20090816 introduces a major pointer bug to pkg_add.

[Steven Drake <sdrake%xnet.co.nz@localhost>]

>Number:         42213
>Category:       pkg
>Synopsis:       pkg_install-20090816 introduces a major pointer bug to pkg_add.
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Oct 22 21:45:00 +0000 2009
>Originator:     Steven Drake
>Release:        Linux 2.6.30
>Environment:
System: Linux idran 2.6.30 #2 PREEMPT Sun Aug 9 18:32:44 NZST 2009 i686 
pentium4 i386
Architecture: pentium4
Machine: i686

>Description:
When i starting upgrading to pkgsrc-2009Q3 i had some werd problems after
i upgraded pkg_install,

1:
pkg_add: exec of install script failed: No such file or directory
pkg_add: 1 package addition failed

2: (when trying to upgrade pkgx [just an exapmle package])
pkg_add: Conflicting PLIST with pkgx-2009Q3: bin/pkgx
pkg_add: 1 package addition failed

3:
The file /pkgdb.byfile.db

I've tracked this down to changes in the following code block:
$NetBSD: main.c,v 1.20 2009/08/16 14:26:46 joerg Exp $

@@ -153,6 +155,19 @@ main(int argc, char **argv)
 
        pkg_install_config();
 
+       if (pkgdb == NULL)
+               pkgdb = _pkgdb_getPKGDB_DIR();
+       PlainPkgdb = xstrdup(pkgdb);
+
+       if (Destdir != NULL) {
+               char *pkgdbdir;
+
+               pkgdbdir = xasprintf("%s/%s", Destdir, pkgdb);
+               _pkgdb_setPKGDB_DIR(pkgdbdir);
+               free(pkgdbdir);
+       } else
+               _pkgdb_setPKGDB_DIR(pkgdb);
+
        process_pkg_path();
        TAILQ_INIT(&pkgs);

I think the following gdb session snippet will show the problem:

Breakpoint 1, main (argc=1, argv=0xbfd8116c) at main.c:168
168                     _pkgdb_setPKGDB_DIR(pkgdb);
1: pkgdb_dir = 0x8091320 "/var/db/pkg"
(gdb) p pkgdb
$1 = 0x8091320 "/var/db/pkg"
(gdb) s
_pkgdb_setPKGDB_DIR (dir=0x8091320 "/var/db/pkg") at pkgdb.c:313
313             (void) snprintf(pkgdb_cache, sizeof(pkgdb_cache), "%s", dir);
1: pkgdb_dir = 0x8091320 "/var/db/pkg"
(gdb) p dir
$2 = 0x8091320 "/var/db/pkg"
(gdb) s
314             pkgdb_dir = pkgdb_cache;
1: pkgdb_dir = 0x8091320 ""

>Fix:
"pkg_add -P / ..." works fine.

or this patch

Index: add/main.c
===================================================================
RCS file: /cvsroot/pkgsrc/pkgtools/pkg_install/files/add/main.c,v
retrieving revision 1.22
diff -u -p -r1.22 main.c
--- add/main.c  7 Oct 2009 12:53:26 -0000       1.22
+++ add/main.c  22 Oct 2009 21:27:41 -0000
@@ -156,6 +156,9 @@ main(int argc, char **argv)
 
        if (pkgdb == NULL)
                pkgdb = _pkgdb_getPKGDB_DIR();
+       else
+               _pkgdb_setPKGDB_DIR(pkgdb);
+
        PlainPkgdb = xstrdup(pkgdb);
 
        if (Destdir != NULL) {
@@ -164,8 +167,7 @@ main(int argc, char **argv)
                pkgdbdir = xasprintf("%s/%s", Destdir, pkgdb);
                _pkgdb_setPKGDB_DIR(pkgdbdir);
                free(pkgdbdir);
-       } else
-               _pkgdb_setPKGDB_DIR(pkgdb);
+       }
 
        process_pkg_path();
        TAILQ_INIT(&pkgs);

-- 
Steven