maps: add the "exists" method to RevMap This is a part of the bigger plan to get rid of reading or writing rev_map directly without going through the RevMap class. Before this patch, there is no easy way to know if the RevMap file exists or not, so the revset functions "fromsvn" and "svnrev" choose to read the rev_map file directly, and throw an exception if the file does not exist. This patch adds the "exists" method that will be used in svnmeta next patch, so these revset functions can test if the file exists without reading the rev_map file directly.

#!/bin/sh
#
# Generate movetotrunk.svndump
#

mkdir temp
cd temp

mkdir project-orig
cd project-orig
cd ..

svnadmin create testrepo
svnurl=file://`pwd`/testrepo
svn mkdir --parents $svnurl/sub1/sub2 -m subpaths
svn import project-orig $svnurl/sub1/sub2 -m "init project"

svn co $svnurl/sub1/sub2 project
cd project
echo a > a
svn add a
mkdir dir
echo b > dir/b
svn add dir
svn ci -m adda
svn up
mkdir trunk
svn add trunk
svn mv a trunk/a
svn mv dir trunk/dir
svn ci -m 'move to trunk'
cd ..

svnadmin dump testrepo > ../movetotrunk.svndump