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$RANDOM incorrectly seeded in subshells

From: Tomas Janousek
Subject: $RANDOM incorrectly seeded in subshells
Date: Fri, 9 Nov 2007 11:01:51 +0100
User-agent: Mutt/1.5.16 (2007-06-09)

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/local/share/locale' -DPACKAGE='bash' 
-DSHELL -DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -g -O2
uname output: Linux tjanouse.englab.brq.redhat.com 2.6.18-8.1.8.el5 #1 SMP Mon 
Jun 25 17:06:19 EDT 2007 i686 i686 i386 GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 3.2
Patch Level: 25
Release Status: release

        If you cause rng to be seeded in a subshell (enclose the command in
        parentheses) and in this same subshell spawn another subshell, rng is
        not seeded as it should be. See the example in Repeat-by.

        $ ( echo $RANDOM; ( echo $RANDOM ); ( echo $RANDOM ) )

        We had a fix in the Fedora package that used subshell_level instead of
        just looking at subshell_environment, but that introduced another
        oddity, since subshell_level is not increased for simple async
        (bugzilla for this one is
        https://bugzilla.redhat.com/show_bug.cgi?id=344411 )

        I'm attaching a patch that was applied over that one, so it just shows
        what the final solution is like, it's not applicable to 3.2 tarball.

Tomas Janousek, SW Engineer, Red Hat, Inc.

Attachment: bash-3.2-344411.patch
Description: Text document

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