[Libguestfs] [PATCH] More complete fix for bash regexp quoting bug.

[Richard W.M. Jones]

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top
-------------- next part --------------
>From 4891ff9945177e8666af8381d1e0a54b8ce363e2 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Tue, 2 Mar 2010 10:34:20 +0000
Subject: [PATCH] More complete fix for bash regexp quoting bug.

Commit 457fccae1b665347 was not a complete fix, in that it
didn't work properly on RHEL 5 era bash (3.2.x).  For example:

  file=libntfs-3g.so.74
  [[ "$file" =~ ^lib(.*)\.so\.([0-9]+)\. ]] && \
    echo "lib${BASH_REMATCH[1]}.so.${BASH_REMATCH[2]}.*"

would on those old shells print:

  libntfs-3g.so.7.*

It seems the final \. was being treated as a plain period (ie.
match anything).

The only way to work around this incompatibility is to assign the
patterns to variables and match on those, ie:

  p='^lib(.*)\.so\.([0-9]+)\.'
  [[ "$file" =~ $p ]] && ...

This works in both old and new shells.
---
 appliance/supermin-split.sh.in |   29 ++++++++++++++++++++---------
 1 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/appliance/supermin-split.sh.in b/appliance/supermin-split.sh.in
index 753fca3..cd29b8a 100755
--- a/appliance/supermin-split.sh.in
+++ b/appliance/supermin-split.sh.in
@@ -55,24 +55,35 @@ for path in $(find -not -name fakeroot.log); do
     # question E14 here http://tiswww.case.edu/php/chet/bash/FAQ and
     # http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=487387#25
     # (RHBZ#566511).
+    p_etc='^\./etc'
+    p_dev='^\./dev'
+    p_var='^\./var'
+    p_lib_modules='^\./lib/modules/'
+    p_builddir='^\./builddir'
+    p_ld_so='^ld-[.0-9]+\.so$'
+    p_libbfd='^libbfd-.*\.so$'
+    p_libgcc='^libgcc_s-.*\.so\.([0-9]+)$'
+    p_lib123so='^lib(.*)-[-.0-9]+\.so$'
+    p_lib123so123='^lib(.*)-[-.0-9]+\.so\.([0-9]+)\.'
+    p_libso123='^lib(.*)\.so\.([0-9]+)\.'
 
     # All we're going to keep are the special files /init, the daemon,
     # configuration files (/etc), devices and modifiable stuff (/var).
     if [ "$path" = "./init" -o "$file" = "guestfsd" ]; then
         echo "$path" >&5
 
-    elif [[ "$path" =~ ^\./etc || "$path" =~ ^\./dev || "$path" =~ ^\./var ]]
+    elif [[ "$path" =~ $p_etc || "$path" =~ $p_dev || "$path" =~ $p_var ]]
     then
         echo "$path" >&5
 
     # Kernel modules are always copied in from the host, including all
     # the dependency files.
-    elif [[ "$path" =~ ^\./lib/modules/ ]]; then
+    elif [[ "$path" =~ $p_lib_modules ]]; then
         :
 
     # On mock/Koji, exclude bogus /builddir directory which for some
     # reason contains some yum temporary files (RHBZ#566512).
-    elif [[ "$path" =~ ^\./builddir ]]; then
+    elif [[ "$path" =~ $p_builddir ]]; then
         :
 
     elif [ -d "$path" ]; then
@@ -82,27 +93,27 @@ for path in $(find -not -name fakeroot.log); do
 
     # Some libraries need fixed version numbers replaced by wildcards.
 
-    elif [[ "$file" =~ ^ld-[.0-9]+\.so$ ]]; then
+    elif [[ "$file" =~ $p_ld_so ]]; then
         echo "$dir/ld-*.so" >&6
 
     # Special case for libbfd
-    elif [[ "$file" =~ ^libbfd-.*\.so$ ]]; then
+    elif [[ "$file" =~ $p_libbfd ]]; then
         echo "$dir/libbfd-*.so" >&6
 
     # Special case for libgcc_s-<gccversion>-<date>.so.N
-    elif [[ "$file" =~ ^libgcc_s-.*\.so\.([0-9]+)$ ]]; then
+    elif [[ "$file" =~ $p_libgcc ]]; then
         echo "$dir/libgcc_s-*.so.${BASH_REMATCH[1]}" >&6
 
     # libfoo-1.2.3.so
-    elif [[ "$file" =~ ^lib(.*)-[-.0-9]+\.so$ ]]; then
+    elif [[ "$file" =~ $p_lib123so ]]; then
         echo "$dir/lib${BASH_REMATCH[1]}-*.so" >&6
 
     # libfoo-1.2.3.so.1.2.3 (but NOT '*.so.N')
-    elif [[ "$file" =~ ^lib(.*)-[-.0-9]+\.so\.([0-9]+)\. ]]; then
+    elif [[ "$file" =~ $p_lib123so123 ]]; then
         echo "$dir/lib${BASH_REMATCH[1]}-*.so.${BASH_REMATCH[2]}.*" >&6
 
     # libfoo.so.1.2.3 (but NOT '*.so.N')
-    elif [[ "$file" =~ ^lib(.*)\.so\.([0-9]+)\. ]]; then
+    elif [[ "$file" =~ $p_libso123 ]]; then
         echo "$dir/lib${BASH_REMATCH[1]}.so.${BASH_REMATCH[2]}.*" >&6
 
     else
-- 
1.6.5.2