get_sha1() shorthands for blob/tree objects

diff --git a/git-cvsimport.perl b/git-cvsimport.perl
index 24f983434249e0c37b7f2229e73c70b374403dc4..c0ae00bda74e68f98efc63c093efb73c7ff914f4 100755 (executable)
--- a/git-cvsimport.perl
+++ b/git-cvsimport.perl
@@ -452,8 +452,8 @@ ($$)
 
 my $last_branch = "";
 my $orig_branch = "";
-my $forward_master = 0;
 my %branch_date;
+my $tip_at_start = undef;
 
 my $git_dir = $ENV{"GIT_DIR"} || ".git";
 $git_dir = getwd()."/".$git_dir unless $git_dir =~ m#^/#;
@@ -488,21 +488,7 @@ ($$)
                $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;
+       $tip_at_start = `git-rev-parse --verify HEAD`;
 
        # populate index
        system('git-read-tree', $last_branch);
@@ -691,11 +677,7 @@ ($$)
        waitpid($pid,0);
        die "Error running git-commit-tree: $?\n" if $?;
 
-       open(C,">$git_dir/refs/heads/$branch")
-               or die "Cannot open branch $branch for update: $!\n";
-       print C "$cid\n"
-               or die "Cannot write branch $branch for update: $!\n";
-       close(C)
+       system("git-update-ref refs/heads/$branch $cid") == 0
                or die "Cannot write branch $branch for update: $!\n";
 
        if($tag) {
@@ -846,8 +828,12 @@ ($$)
                        print "Drop $fn\n" if $opt_v;
                } else {
                        print "".($init ? "New" : "Update")." $fn: $size bytes\n" if $opt_v;
-                       open my $F, '-|', "git-hash-object -w $tmpname"
+                       my $pid = open(my $F, '-|');
+                       die $! unless defined $pid;
+                       if (!$pid) {
+                           exec("git-hash-object", "-w", $tmpname)
                                or die "Cannot create object: $!\n";
+                       }
                        my $sha = <$F>;
                        chomp $sha;
                        close $F;
@@ -885,17 +871,26 @@ ($$)
 
 # 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 $forward_master;
-       unless ($opt_i) {
-               system('git-read-tree', '-m', '-u', 'CVS2GIT_HEAD', 'HEAD');
-               die "read-tree failed: $?\n" if $?;
+       print "DONE.\n" if $opt_v;
+       if ($opt_i) {
+               exit 0;
+       }
+       my $tip_at_end = `git-rev-parse --verify HEAD`;
+       if ($tip_at_start ne $tip_at_end) {
+               for ($tip_at_start, $tip_at_end) { chomp; }
+               print "Fetched into the current branch.\n" if $opt_v;
+               system(qw(git-read-tree -u -m),
+                      $tip_at_start, $tip_at_end);
+               die "Fast-forward update failed: $?\n" if $?;
+       }
+       else {
+               system(qw(git-merge cvsimport HEAD), "refs/heads/$opt_o");
+               die "Could not merge $opt_o into the current branch.\n" if $?;
        }
 } 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")
+       system("git-update-ref", "refs/heads/master", "refs/heads/$opt_o")
                unless -f "$git_dir/refs/heads/master";
        system('git-update-ref', 'HEAD', "$orig_branch");
        unless ($opt_i) {
@@ -903,4 +898,3 @@ ($$)
                die "checkout failed: $?\n" if $?;
        }
 }
-unlink("$git_dir/CVS2GIT_HEAD");