X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=dgit;h=ef815997de84c0e581f3f4d7bf3347ebcb64dd08;hb=4fcc733b6194bdee895424cab72874e98ea42816;hp=88df4ef5eedeaf0bca604e477067dc2b53d18b49;hpb=893e94307ff001da9fc13b28c94ed27d17f48b60;p=dgit.git

diff --git a/dgit b/dgit
index 88df4ef5..ef815997 100755
--- a/dgit
+++ b/dgit
@@ -5281,9 +5281,25 @@ sub cmd_import_dsc {
 
     badusage "dry run makes no sense with import-dsc" unless act_local();
 
+    my $force = $dstbranch =~ s/^\+//   ? +1 :
+	        $dstbranch =~ s/^\.\.// ? -1 :
+                                           0;
+    my $info = $force ? " $&" : '';
+    $info = "$dscfn$info";
+
+    my $specbranch = $dstbranch;
     $dstbranch = "refs/heads/$dstbranch" unless $dstbranch =~ m#^refs/#;
     $dstbranch = cmdoutput @git, qw(check-ref-format --normalize), $dstbranch;
 
+    my @symcmd = (@git, qw(symbolic-ref -q HEAD));
+    my $chead = cmdoutput_errok @symcmd;
+    defined $chead or $?==256 or failedcmd @symcmd;
+
+    fail "$dstbranch is checked out - will not update it"
+	if defined $chead and $chead eq $dstbranch;
+
+    my $oldhash = git_get_ref $dstbranch;
+
     open D, "<", $dscfn or fail "open import .dsc ($dscfn): $!";
     $dscdata = do { local $/ = undef; <D>; };
     D->error and fail "read $dscfn: $!";
@@ -5305,13 +5321,27 @@ Your git tree does not have that object.  Try `git fetch' from a
 plausible server (browse.dgit.d.o? alioth?), and try the import-dsc again.
 END
 	}
-	@cmd = (@git, qw(update-ref -m), "dgit import-dsc (Dgit): $dscfn",
+	if ($oldhash && !is_fast_fwd $oldhash, $dgit_commit) {
+	    if ($force > 0) {
+		progress "Not fast forward, forced update.";
+	    } else {
+		fail "Not fast forward to $dgit_commit";
+	    }
+	}
+	@cmd = (@git, qw(update-ref -m), "dgit import-dsc (Dgit): $info",
 		$dstbranch, $dgit_commit);
 	runcmd @cmd;
 	progress "dgit: import-dsc updated git ref $dstbranch";
 	return 0;
     }
 
+    fail <<END
+Branch $dstbranch already exists
+Specify ..$specbranch for a pseudo-merge, binding in existing history
+Specify  +$specbranch to overwrite, discarding existing history
+END
+	if $oldhash && !$force;
+
     $package = getfield $dsc, 'Source';
     my @dfi = dsc_files_info();
     foreach my $fi (@dfi) {
@@ -5337,8 +5367,29 @@ END
     my @mergeinputs = generate_commits_from_dsc();
     die unless @mergeinputs == 1;
 
-    my @cmd = (@git, qw(update-ref -m), "dgit import-dsc: $dscfn",
-	       $dstbranch, $mergeinputs[0]{Commit});
+    my $newhash = $mergeinputs[0]{Commit};
+
+    if ($oldhash) {
+	if ($force > 0) {
+	    progress "Import, forced update - synthetic orphan git history.";
+	} elsif ($force < 0) {
+	    progress "Import, merging.";
+	    my $tree = cmdoutput @git, qw(rev-parse), "$newhash:";
+	    my $version = getfield $dsc, 'Version';
+	    $newhash = make_commit_text <<END;
+tree $tree
+parent $newhash
+parent $oldhash
+
+Merge $package ($version) import into $dstbranch
+END
+	} else {
+	    die; # caught earlier
+	}
+    }
+
+    my @cmd = (@git, qw(update-ref -m), "dgit import-dsc: $info",
+	       $dstbranch, $newhash);
     runcmd @cmd;
     progress "dgit: import-dsc results are in in git ref $dstbranch";
 }