Document the new migration tool

diff --git a/git-cvsimport-script b/git-cvsimport-script
index d61175613dc4ca522642d9113d7e54a5dfb03cf2..0d205c55aa60a65e1157d3cf508c0835bde1c272 100755 (executable)
--- a/git-cvsimport-script
+++ b/git-cvsimport-script
@@ -61,6 +61,8 @@ package CVSconn;
 # Basic CVS dialog.
 # We're only interested in connecting and downloading, so ...
 
+use POSIX qw(strftime dup2);
+
 sub new {
        my($what,$repo,$subdir) = @_;
        $what=ref($what) if ref($what);
@@ -321,6 +323,7 @@ sub getwd() {
 chdir($git_tree);
 
 my $last_branch = "";
+my $orig_branch = "";
 my %branch_date;
 
 my $git_dir = $ENV{"GIT_DIR"} || ".git";
@@ -333,9 +336,14 @@ unless(-d $git_dir) {
        die "Cannot init an empty tree: $?\n" if $?;
 
        $last_branch = $opt_o;
+       $orig_branch = "";
 } else {
        $last_branch = basename(readlink("$git_dir/HEAD"));
-       die "Cannot read the last branch name: $!\n" unless $last_branch;
+       unless($last_branch) {
+               warn "Cannot read the last branch name: $! -- assuming 'master'\n";
+               $last_branch = "master";
+       }
+       $orig_branch = $last_branch;
 
        # Get the last import timestamps
        opendir(D,"$git_dir/refs/heads");
@@ -556,8 +564,8 @@ while(<CVS>) {
                }
                if(($ancestor || $branch) ne $last_branch) {
                        print "Switching from $last_branch to $branch\n" if $opt_v;
-                       system("git-read-tree -m -u $last_branch $branch");
-                       die "read-tree $branch failed at $branch: $?\n" if $?;
+                       system("git-read-tree","-m","-u","$last_branch","$branch");
+                       die "read-tree failed: $?\n" if $?;
                }
                if($branch ne $last_branch) {
                        unlink("$git_dir/HEAD");
@@ -571,7 +579,9 @@ while(<CVS>) {
 #      VERSION:1.96->1.96.2.1
                my $init = ($2 eq "INITIAL");
                my $fn = $1;
-               my $data = $cvs->file($fn,$3);
+               my $rev = $3;
+               $fn =~ s#^/+##;
+               my $data = $cvs->file($fn,$rev);
                print "".($init ? "New" : "Update")." $fn: ".length($data)." bytes.\n";
                mkpath(dirname($fn),$opt_v);
                open(F,"> ./$fn")
@@ -583,7 +593,9 @@ while(<CVS>) {
                chmod(pmode($cvs->{'mode'}), $fn);
                push(@new,$fn); # may be resurrected!
        } elsif($state == 9 and /^\s+(\S+):\d(?:\.\d+)+->(\d(?:\.\d+)+)\(DEAD\)\s*$/) {
-               push(@old,$1);
+               my $fn = $1;
+               $fn =~ s#^/+##;
+               push(@old,$fn);
        } elsif($state == 9 and /^\s*$/) {
                $state = 10;
        } elsif(($state == 9 or $state == 10) and /^-+$/) {
@@ -599,4 +611,19 @@ while(<CVS>) {
 }
 &$commit() if $branch and $state != 11;
 
-print "DONE\n" if $opt_v;
+# Now switch back to the branch we were in before all of this happened
+if($orig_branch) {
+       print "DONE; switching back to $orig_branch\n" if $opt_v;
+} else {
+       $orig_branch = "master";
+       print "DONE; creating $orig_branch branch\n" if $opt_v;
+       system("cp","$git_dir/refs/heads/$opt_o","$git_dir/refs/heads/master")
+               unless -f "$git_dir/refs/heads/master";
+}
+
+system("git-read-tree","-m","-u","$last_branch","$orig_branch");
+die "read-tree failed: $?\n" if $?;
+
+unlink("$git_dir/HEAD");
+symlink("refs/heads/$orig_branch","$git_dir/HEAD");
+