How do I fix SVN 'Working copy text base is corrupt'?

I got this following error when I am trying to check-in and for fixing this error bash script is given below. I just want to know what the bash script does and what is the root cause of the failure. Please help me.
=======bash script for fixing====================
#!/bin/bash

set -e


usage(){
echo "Error $errcode $errorcode at line ${BASH_LINENO[0]} while executing: $BASH_COMMAND"
exit $errorcode
}
trap usage ERR

file="$1"

[ -f "$file" ] # must be a file


url=$(svn info "$file" | grep '^URL' | awk '{print $2}')
root=$(svn info "$file" | grep '^Working Copy Root' | awk -F':' '{print $2}')
rev=$(svn info "$file" | grep '^Revision' | awk -F':' '{print $2}')

name="$(basename $url)"
dir="$(dirname $url)"

tmp="$(mktemp -d .tmp.XXX)"


echo "Doing fresh checkout for: $name"
echo " URL: $dir"
echo " dest: $tmp"
echo " rev: $rev"

svn co -N -r $rev "$dir" "$tmp" >> /dev/null
hash=$(cd "$tmp" && sha1sum "$name" | awk '{print $1}')
corrupt=$(find ${root}/.svn/pristine -name $hash.svn-base)
svnbase=$(find ${tmp}/.svn/pristine -name $hash.svn-base)

corrupt_sum=$(md5sum "$corrupt" | awk '{print $1}')
svnbase_sum=$(md5sum "$svnbase" | awk '{print $1}')

if [[ "$corrupt_sum" != "$svnbase_sum" ]]
then
echo "Fixing .svn-base for $name"
echo " from: $corrupt_sum (corrupted)"
echo " to: $svnbase_sum (expected)"
echo " src: $svnbase"
echo " dest: $corrupt"
cp $svnbase $corrupt
else
echo "No corruption detected"
fi

rm -rf "$tmp"
====================