git-cvsimport-script: move working directory forward

If HEAD happened to point to a cvs branch, move the
working directory forward to the tip of the branch.
Additionally, if master and "origin" are equal,
move master forward to new origin first.

diff --git a/git-cvsimport-script b/git-cvsimport-script
index 3e6d22e..cdf9891 100755 (executable)
--- a/git-cvsimport-script
+++ b/git-cvsimport-script
@@ -372,6 +372,7 @@ chdir($git_tree);
 
 my $last_branch = "";
 my $orig_branch = "";
+my $forward_master = 0;
 my %branch_date;
 
 my $git_dir = $ENV{"GIT_DIR"} || ".git";
@@ -403,6 +404,21 @@ unless(-d $git_dir) {
                $last_branch = "master";
        }
        $orig_branch = $last_branch;
+       if (-f "$git_dir/CVS2GIT_HEAD") {
+               die <<EOM;
+CVS2GIT_HEAD exists.
+Make sure your working directory corresponds to HEAD and remove CVS2GIT_HEAD.
+You may need to run
+
+    git-read-tree -m -u CVS2GIT_HEAD HEAD
+EOM
+       }
+       system('cp', "$git_dir/HEAD", "$git_dir/CVS2GIT_HEAD");
+
+       $forward_master =
+           $opt_o ne 'master' && -f "$git_dir/refs/heads/master" &&
+           system('cmp', '-s', "$git_dir/refs/heads/master", 
+                               "$git_dir/refs/heads/$opt_o") == 0;
 
        # populate index
        system('git-read-tree', $last_branch);
@@ -695,9 +711,19 @@ while(<CVS>) {
 
 unlink($git_index);
 
+if (defined $orig_git_index) {
+       $ENV{GIT_INDEX_FILE} = $orig_git_index;
+} else {
+       delete $ENV{GIT_INDEX_FILE};
+}
+
 # Now switch back to the branch we were in before all of this happened
 if($orig_branch) {
        print "DONE\n" if $opt_v;
+       system("cp","$git_dir/refs/heads/$opt_o","$git_dir/refs/heads/master")
+               if $forward_master;
+       system('git-read-tree', '-m', '-u', 'CVS2GIT_HEAD', 'HEAD');
+       die "read-tree failed: $?\n" if $?;
 } else {
        $orig_branch = "master";
        print "DONE; creating $orig_branch branch\n" if $opt_v;
@@ -705,11 +731,7 @@ if($orig_branch) {
                unless -f "$git_dir/refs/heads/master";
        unlink("$git_dir/HEAD");
        symlink("refs/heads/$orig_branch","$git_dir/HEAD");
-       if (defined $orig_git_index) {
-           $ENV{GIT_INDEX_FILE} = $orig_git_index;
-       } else {
-           delete $ENV{GIT_INDEX_FILE};
-       }
        system('git checkout');
        die "checkout failed: $?\n" if $?;
 }
+unlink("$git_dir/CVS2GIT_HEAD");