Allow forcing of a parent commit, even if the parent is not a direct one.

This can be used to compress multiple changesets into one, for example
like

	git cvsexportcommit -P cvshead mybranch

without having to do so in git first.

Signed-off-by: Simon 'corecode' Schubert <corecode@fs.ei.tum.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-cvsexportcommit.txt

@@ -8,7 +8,7 @@ git-cvsexportcommit - Export a single commit to a CVS checkout
 
 SYNOPSIS
 --------
-'git-cvsexportcommit' [-h] [-v] [-c] [-p] [-a] [-f] [-m msgprefix] [PARENTCOMMIT] COMMITID
+'git-cvsexportcommit' [-h] [-v] [-c] [-P] [-p] [-a] [-f] [-m msgprefix] [PARENTCOMMIT] COMMITID
 
 
 DESCRIPTION
@@ -46,6 +46,9 @@ OPTIONS
 -f::
 	Force the merge even if the files are not up to date.
 
+-P::
+	Force the parent commit, even if it is not a direct parent.
+
 -m::
 	Prepend the commit message with the provided prefix. 
 	Useful for patch series and the like.

git-cvsexportcommit.perl

@@ -15,9 +15,9 @@ unless ($ENV{GIT_DIR} && -r $ENV{GIT_DIR}){
     die "GIT_DIR is not defined or is unreadable";
 }
 
-our ($opt_h, $opt_p, $opt_v, $opt_c, $opt_f, $opt_a, $opt_m );
+our ($opt_h, $opt_P, $opt_p, $opt_v, $opt_c, $opt_f, $opt_a, $opt_m );
 
-getopts('hpvcfam:');
+getopts('hPpvcfam:');
 
 $opt_h && usage();
 
@@ -89,7 +89,7 @@ if ($parent) {
 	    last;
 	}; # found it
     }
-    die "Did not find $parent in the parents for this commit!" if !$found;
+    die "Did not find $parent in the parents for this commit!" if !$found and !$opt_P;
 } else { # we don't have a parent from the cmdline...
     if (@parents == 1) { # it's safe to get it from the commit
 	$parent = $parents[0];