tests/svn/svndump-branches.sh

filectx: add isabsent method

This will indicate whether this filectx represents a file that is *not* in a
changectx. This will be used by merge and filemerge code to know about when a
conflict is a change/delete conflict.

While this is kind of hacky, it is the least bad of all the alternatives. Other
options considered but rejected include:
- isinstance(fctx, ...) -- not very Pythonic, doesn't support duck typing
- fctx.size() is None -- the 'size()' call on workingfilectxes causes a disk stat
- fctx.filenode() == nullid -- the semantics around filenode are incredibly
  confusing. In particular, for workingfilectxes, filenode() is always None no
  matter whether the file is present on disk or in either parent. Having different
  behavior for None versus nullid in the merge code is just asking for pain.

Thanks to Pierre-Yves David for early review feedback here.

#!/bin/sh
#
# Use this script to generate branches.svndump
#

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir trunk
mkdir branches
cd ..

svnadmin create svn-repo
svnurl=file://`pwd`/svn-repo
svn import project-orig $svnurl -m "init projA"

svn co $svnurl project
cd project
echo a > trunk/a
echo b > trunk/b
echo c > trunk/c
mkdir trunk/dir
echo e > trunk/dir/e
# Add a file within branches, used to confuse branch detection
echo d > branches/notinbranch
svn add trunk/a trunk/b trunk/c trunk/dir branches/notinbranch
svn ci -m hello
svn up

# Branch to old
svn copy trunk branches/old
svn rm branches/old/c
svn rm branches/old/dir
svn ci -m "branch trunk, remove c and dir"
svn up

# Update trunk
echo a >> trunk/a
svn ci -m "change a"

# Update old branch
echo b >> branches/old/b
svn ci -m "change b"

# Create a cross-branch revision
svn move trunk/b branches/old/c
echo c >> branches/old/c
svn ci -m "move and update c"

# Update old branch again
echo b >> branches/old/b
svn ci -m "change b again"

# Move back and forth between branch of similar names
# This used to generate fake copy records
svn up
svn move branches/old branches/old2
svn ci -m "move to old2"
svn move branches/old2 branches/old
svn ci -m "move back to old"

# Update trunk again
echo a > trunk/a
svn ci -m "last change to a"

# Branch again from a converted revision
svn copy -r 1 $svnurl/trunk branches/old3
svn ci -m "branch trunk@1 into old3"
cd ..

svnadmin dump svn-repo > ../branches.svndump