Re: RFC: Enabling or disabling tracing shell functions

[Chet Ramey]

On 6/6/16 12:50 AM, Dan Douglas wrote:
> On Sun, Jun 5, 2016 at 8:48 PM, Chet Ramey  wrote:
>> "Traced functions inherit the DEBUG  and  RETURN  traps  from  the  calling
>> shell."
> 
> Why did RETURN originally get sucked into set -T? Was it supposed to
> be primarily for debugging? 

Yes.  The RETURN trap was added to bash 14 years ago as part of the support
for the bash debugger.  The conditions under which it's inherited are the
same as DEBUG.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRUc...@case.eduhttp://cnswww.cns.cwru.edu/~chet/

Re: read builtin doesnt save partial reads on timeout

[Chet Ramey]

On 6/6/16 10:01 AM, George Schwab wrote:

> Bash Version: 4.3
> Patch Level: 11
> Release Status: release
> 
> Description:
> The read builtin does not appear to save partial reads to the
> variable when a timeout has occured.
> This is contrary to the documentation which states 'read saves any
> partial input read into the specified variable'
>
> https://www.gnu.org/software/bash/manual/html_node/Bash-Builtins.html#Bash-Builtins
> Perhaps this is just an error in the documentation. either way,
> should be fixed, right?
> A friend has tested this on 4.4.0(1)-rc2 as well.
> 
> Repeat-By:
> read -N2 -t1 < <(printf x; sleep 2; printf y); echo "$REPLY"

$ ../bash-4.3-patched/bash --version
GNU bash, version 4.3.42(28)-release (x86_64-apple-darwin12.5.0)
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
$ cat x26
read -N2 -t1 < <(printf x; sleep 2; printf y); echo "$REPLY : $?"
$ ../bash-4.3-patched/bash ./x26
x : 142

> { read -t1 a; read b; } < <(printf x; sleep 2; printf y); echo
> "<$a><$b>"

I get  with this example.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRUc...@case.eduhttp://cnswww.cns.cwru.edu/~chet/

Re: a == a[0] convention

[Dan Douglas]

On Thu, Jun 2, 2016 at 12:18 PM, Grisha Levit  wrote:
> I think all of the stuff here is fixed in the latest devel snapshot

Ah ok I tried this again. Yes this looks better now, thanks.

> there is definitely weirdness if you run the assignments as a typeset
> command.  I hadn't even tried the ref4 case, which gives the weirdest
> results when used with typeset/declare:
> https://groups.google.com/forum/#!topic/gnu.bash.bug/Z-lf3KEnZ34

That's what reminded me of this, but your example was definitely a bug
(regression since 4.3 at least). The ref4[0] one is just an odd
special case but I think it's probably easier to treat it as an error.

Re: bash: Please make bash build reproducibly

[Ximin Luo]

Control: tags -1 + patch

I've attached the full Debian patch to make bash 4.3-14 reproducible, that 
includes Reiner's from above.

It also includes *fixing a bug in upstream bash*, which currently 
does-not-appear-in-the-wild *only because* distros already happen to be working 
around it. But upstream really should fix it - i.e. to fix the PGRP_PIPE check 
in configure/configure.ac to account for Linux 4+.

I decided to just set PGRP_PIPE unconditionally in configure.ac and configure, 
because I figure nobody will ever again use linux 0, 1 or 2 so it's not worth 
the extra complexity (which only gives a minor performance gain anyway, as 
opposed to having *incorrect behaviour*). Upstream is free to choose whichever 
behaviour he wants - either this simpler version, or the more complex version 
from my previous email quoted below. Both are correct, if I understand right, 
and when either is applied to upstream, all distros (including Debian) can drop 
our specific patches for PGRP_PIPE.

To re-iterate again, this does not solve the longer-term issue of "installing 
config.h is bad".

Ximin

Ximin Luo:
> (Chet, your specific attention is required for this email, please)
> 
> Ximin Luo:
>> On Sat, 28 May 2016 13:38:35 +0200 Reiner Herrmann  
>> wrote:
>>> After that, the only remaining issue is that the included header file
>>> /usr/include/bash/config.h varies depending on the kernel version used
>>> during build [1] (with kernel <4, PGRP_PIPE is defined).
>>
>> For this particular example, we can just patch this out, i.e. remove it from 
>> the installed config.h. Debian already forces PGRP_PIPE 1 in config-bot.h, 
>> which config.h includes at the end.
>>
> 
> I dug into this a bit more and it looks like the cause of the difference is 
> this snippet from configure.ac:
> 
> linux*) LOCAL_LDFLAGS=-rdynamic  # allow dynamic loading
> case "`uname -r`" in
> 2.[[456789]]*|3*)   AC_DEFINE(PGRP_PIPE) ;;
> esac ;;
> 
> 
> This was added between bash-3.0.16 and bash-3.1, way before Linux 4 came out. 
> So I wonder if this snippet should instead be:
> 
> linux*) LOCAL_LDFLAGS=-rdynamic  # allow dynamic loading
> case "`uname -r`" in
> 1.*|2.[[0123]]*) true ;;
> *) AC_DEFINE(PGRP_PIPE) ;;
> esac ;;
> 
> to set this for all future kernels? Then Debian (and probably other distros) 
> could get rid of our patch, too.
> 
> However, the question still remains why config.h is installed into the 
> end-user system, and if bash-built-with-linux-5 required PGRP_PIPE to be 
> *undefined*, we would still have a reproducibility problem.
> 
> Ximin
> 


-- 
GPG: ed25519/56034877E1F87C35
GPG: rsa4096/1318EFAC5FBBDBCE
git://github.com/infinity0/pubkeys.git
diff -Nru bash-4.3/debian/changelog bash-4.3/debian/changelog
--- bash-4.3/debian/changelog   2015-09-01 01:04:48.0 +0200
+++ bash-4.3/debian/changelog   2016-06-07 11:56:09.0 +0200
@@ -1,3 +1,15 @@
+bash (4.3-14.0~reproducible1) UNRELEASED; urgency=medium
+
+  [ Ximin Luo ]
+  * Non-maintainer upload.
+  * Set PGRP_PIPE unconditionally on Linux, reproducibly.
+
+  [ Reiner Herrmann ]
+  * Use the system man2html instead of the embedded one, for better build
+reproducibility.
+
+ -- Ximin Luo   Tue, 07 Jun 2016 11:56:07 +0200
+
 bash (4.3-14) unstable; urgency=medium
 
   * Apply upstream patches 040 - 042.
diff -Nru bash-4.3/debian/control bash-4.3/debian/control
--- bash-4.3/debian/control 2015-01-28 17:13:32.0 +0100
+++ bash-4.3/debian/control 2016-06-06 03:00:38.0 +0200
@@ -5,7 +5,7 @@
 Standards-Version: 3.9.6
 Build-Depends: autoconf, autotools-dev, bison, libncurses5-dev,
  texinfo, texi2html, debhelper (>= 5), locales, gettext, sharutils, time,
- xz-utils, dpkg-dev (>= 1.16.1)
+ xz-utils, dpkg-dev (>= 1.16.1), man2html
 Build-Depends-Indep: texlive-latex-base, ghostscript, texlive-fonts-recommended
 Homepage: http://tiswww.case.edu/php/chet/bash/bashtop.html
 Vcs-Browser: https://code.launchpad.net/~doko/+junk/pkg-bash-debian
diff -Nru bash-4.3/debian/patches/pgrp-pipe.diff 
bash-4.3/debian/patches/pgrp-pipe.diff
--- bash-4.3/debian/patches/pgrp-pipe.diff  2013-10-23 14:41:22.0 
+0200
+++ bash-4.3/debian/patches/pgrp-pipe.diff  2016-06-07 12:17:05.0 
+0200
@@ -1,11 +1,43 @@
-# DP: Define PGRP_PIPE to avoid race condition.
-
 a/config-bot.h
-+++ b/config-bot.h
-@@ -197,3 +197,6 @@
- 
- /* If you don't want bash to provide a default mail file to check. */
- #undef DEFAULT_MAIL_DIRECTORY
-+
-+/* Bug #224543 */
-+#define PGRP_PIPE 1
+Description: Set PGRP_PIPE unconditionally on Linux, reproducibly
+ The original fix to #224543 involved defining this unconditionally in
+ config-bot.h. Unfortunately, upstream has a check in configure.ac that defines
+ this conditionally in config.h, which makes the bash-builtins package 
+ unreproducible between different kernels. Here, we adopt a different approach,
+ which is to turn upstream's de