Bug 681940

bashbug-32 is unable to send this from mock I've tried manually sending it via bashbug etc... nothing seems to work. Perhaps as maintainer you have upstream contact?

Subject: change in case evaluation handling

Configuration Information [Automatically generated, do not change]:
Machine: i386
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i386' -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i386-redhat-linux-gnu' -DCONF_VENDOR='redhat' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -DDEBUG -DMALLOC_DEBUG -I.  -I. -I./include -I./lib  -D_GNU_SOURCE -DRECYCLES_PIDS -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables
uname output: Linux iridium.gnat.ca 2.6.35.11-83.fc14.x86_64 #1 SMP Mon Feb 7 07:06:44 UTC 2011 i686 i686 i386 GNU/Linux
Machine Type: i386-redhat-linux-gnu

Bash Version: 4.2
Patch Level: 0
Release Status: rc2

Description:
	The following script illustrates a regression in handline case evaluations

case x"" in
  x) echo 'expected'
     ;;
  x??) echo 'this would be really odd'
     ;;
  x?) echo 'does this prove anything?'
      echo x""x
     ;;
  *) echo 'no match'
     ;;
esac

as output you get:

=>	does this prove anything
	xx

In bash 4.1.X you would get as output 'expected'. The issue was found by configure failing with lines like
case x"$enable_feature" in where enable_feature hadn't been passed to configure so the variable was undefined.
I should note that handling

if [ x"$some_undefined_var" = x ]; continues to function the same way as previous versions

Repeat-By:
	using the following script (named test_script for me):
======================================
#!/bin/sh

case x"$mytest" in
 xyes)
  echo "yes"
  ;;
 xno)
  echo "no"
  ;;
 x)
  echo "empty"
  ;;
 *)
  echo "not supported"
  ;;
esac

mytest=$1
case x"$mytest" in
 xyes)
  echo "yes"
  ;;
 xno)
  echo "no"
  ;;
 x)
  echo "empty"
  ;;
 *)
  echo "not supported"
  ;;
esac

exit;
=========================================

and call it with 

sh test_script yes
sh test_script no
sh test_script whatever
sh test_script

4.1.X has the following output:

- sh test_script yes
empty
yes

- sh test_script no
empty
no

- sh test_script whatever
empty
not supported

- sh test_script
empty
empty 

4.2.0 has the following output:
- sh test_script yes
not supported
yes

- sh test_script no
not supported
no

- sh test_script whatever
not supported
not supported

- sh test_script
not supported
not supported

Thanks for the report. Reported upstream.

Sooner or later it will be visible at http://lists.gnu.org/archive/html/bug-bash/2011-03/threads.html

thanks - I'll keep tabs on that.

Created attachment 482143 [details]
Patch from upstream

Can you please try this patch? It comes from upstream.

Created attachment 482160 [details]
How bash was built

Just the git diff of current bash git head to my checkout and changes.

Worse... Using http://fpaste.org/C018/

mock-chroot> sh test yes
empty
empty

mock-chroot> sh test
empty
empty

mock-chroot> sh test no
empty
empty

mock-chroot> sh test whatever
empty
empty


Vs F14:

> sh test yes
empty
yes

> sh test 
empty
empty

> sh test no
empty
no

> sh test whatever
empty
not supported

Also you can see my bash package used for testing at 

http://iridium.gnat.ca/~gnat/smock/yum/fedora-15/i386

I get the same results in F14 and rawhide bash (with the patch). The site http://iridium.gnat.ca/~gnat/smock/yum/fedora-15/i386 is not accessible for me.

(In reply to comment #5)
> Created attachment 482143 [details]
> Patch from upstream
> 
> Can you please try this patch? It comes from upstream.

This patch seems to work for me (patch applied against bash-4.2.6-1.fc15
src.rpm)

bash-4.2.7-1.fc15 has been submitted as an update for Fedora 15.
https://admin.fedoraproject.org/updates/bash-4.2.7-1.fc15

bash-4.2.7-1.fc15 has been pushed to the Fedora 15 testing repository.  If problems still persist, please make note of it in this bug report.
 If you want to test the update, you can install it with 
 su -c 'yum --enablerepo=updates-testing update bash'.  You can provide feedback for this update here: https://admin.fedoraproject.org/updates/bash-4.2.7-1.fc15

bash-4.2.7-1.fc15 has been pushed to the Fedora 15 stable repository.  If problems still persist, please make note of it in this bug report.