.links

#!/bin/sh

# Task: go through the files in $RPM_BUILD_ROOT and
# relink symbolic links so that:
# links crossing top level directory boundaries (/usr/* -> /etc/*)
#   are absolute links
# links below one top level directory (/usr/bin/* -> /usr/lib/*)
#   are relative links
# NOTE: we're not doing this to fix a problem (as no matter how you
#   do it you fix one problem by creating another). We're doing it
#   so we can document this as policy - so you can rely on it

# Additional Task: check some usual errors arround symlinks e.g.
#   dangling symlinks or symlinks to init scripts in wrong location

# Author: Stephan Kulow <coolo@suse.de>

# If using normal root, avoid changing anything.
if [ -z "$RPM_BUILD_ROOT" ]; then
    exit 0
fi

LC_ALL=
LANG=
LC_TIME=POSIX

BASENAME=/usr/bin/basename
DIRNAME=/usr/bin/dirname
READLINK=/usr/bin/readlink

cd $RPM_BUILD_ROOT

had_errors=0

links=`find . -type l | sed -e "s,^./,/,"`
for link in $links
do
        link_dest=`$READLINK ./$link`
        orig_link_dest=$link_dest

        new_link_dest=NONE
        link_dir=`$DIRNAME $link`

        case $link_dest in
    .|..|../..) # link to current dir
        continue ;;
    .*) # relative links up
        link_dest="$link_dir/$link_dest"
        ;;
                /*) # absolute links
        ;;
                */*) # relative links down
        link_dest="$link_dir/$link_dest"
        ;;
    *) # the rest
        continue
        esac

        # cleaning out double slash
        link_dest=`echo $link_dest | sed -e 's,//*,/,g; s,/\.$,/,; s,/$,,'`

        # eliminating /./ components
        link_dest=`echo $link_dest | sed -e "s,/\./,/,g"`;

        counter=0
        # eliminating back references
        while echo $link_dest | egrep -q '/\.\.'; do
             link_dest=`echo $link_dest | sed -e "s,/[^/]*/\.\.,,"`;
             case $link_dest in
    /..*) # this is very mean
            echo "ERROR: $link points to illegal $link_dest"
            exit 1
            ;;
    esac
    counter=$((counter + 1))
    if test $counter -gt 10; then
            echo "ERROR: more than 10 back references in $link?"
            exit 1
    fi
        done

        # black list
        case "$link,$link_dest" in
    *,/var/lib/named*)
            continue;;
    /usr/etc,*|/usr/tmp,*)
            continue;;
    */share/texmf/*|/usr/share/terminfo/*)
             continue;;
    *share/automake-*)
             echo "ERROR: link target $link points into automake directory"
             echo " You might want to add a -c to the automake call (or just"
             echo " skip the files from packaging)"
             exit 1
             ;;
    *,/opt/kde3/share/doc/HTML/*/common) # white listed for not existant
             ;;
    *,/proc/*) # links pointing into /proc file system
             ;;
    *)
        if test ! -L ./$link_dest && test ! -e $link_dest && test ! -e ./$link_dest; then
            echo "ERROR: link target doesn't exist (neither in build root nor in installed system):"
            echo "  $link -> $link_dest"
            echo "Add the package providing the target to neededforbuild and Requires"
            test "$NO_BRP_STALE_LINK_ERROR" != "yes" && had_errors=1
        fi
        ;;
        esac

        forced_absolute=0
        for prefix in /usr/X11R6/lib/X11 /usr/X11R6/include/X11 /usr/X11R6/lib/X11/app-defaults ; do
            if echo $link | grep -q "^$prefix/"; then
     if echo $link_dest | grep -q "^$prefix/"; then
            # if it's below it, it's fine
            :
                 else
            forced_absolute=1
                 fi
            fi
        done

        dest_dir=`$DIRNAME $link_dest`

        # figuring out (currently) correct destination
        if test "$link_dir" = "$dest_dir" || test "$dest_dir" = "."; then
    new_link_dest=`$BASENAME $link_dest`
        else
    # figuring out top level directory
    top_link=`echo $link | sed -e 's,^\(/[^/]*\)/.*,\1,'`
                top_dest=`echo $link_dest | sed -e 's,^\(/[^/]*\)/.*,\1,'`
    if test "$forced_absolute" = 0 && test "$top_link" = "$top_dest"; then # supposed to be relative

            # first we need to cut out the common prefix
            link_tmp=$link
            while test "$top_link" = "$top_dest"; do
        link_orig=$link_tmp
        dest_orig=$link_dest
        link_tmp=`echo $link_tmp | sed -e 's,^\(/[^/]*\)/,/,'`
        link_dest=`echo $link_dest | sed -e 's,^\(/[^/]*\)/,/,'`
        top_link=`echo $link_tmp | sed -e 's,^\(/[^/]*\)/.*,\1,'`
        top_dest=`echo $link_dest | sed -e 's,^\(/[^/]*\)/.*,\1,'`

        if test "$top_dest" = "$dest_orig" || test "$top_link" = "$link_orig"; then
                link_tmp=$link_orig
                link_dest=$dest_orig
                break
        fi
            done

            # now we add a .. for every directory component
            link_tmp=`$DIRNAME $link_tmp`

            if test "$link_tmp" = "$link_dest"; then
        new_link_dest=.
            elif test "$link_tmp" != "/"; then # we have a directory component
        link_rel=

        while test -n "$link_tmp"; do
                link_tmp=`echo $link_tmp | sed -e 's,^\(/[^/]*\),,'`
                link_rel="../$link_rel"
        done

        new_link_dest=`echo $link_rel/$link_dest | sed -e "s,//*,/,g"`
            else
        # get rid of the slash
        link_dest=`echo $link_dest | sed -e 's,^/,,'`
        new_link_dest=$link_dest
            fi
    else
            new_link_dest=$link_dest
    fi
        fi

        if test "$new_link_dest" != NONE && test "$new_link_dest" != "$orig_link_dest"; then
    #echo "INFO: relinking $link -> $new_link_dest (was $orig_link_dest)"
    rm ./$link && ln -s $new_link_dest ./$link
        fi
done

if test "$had_errors" = 1; then
        exit 1
fi