[PATCH] import-tars: support hard links

[Johannes Schindelin <johannes.schindelin@gmx.de>]

Previously, we simply treated hard links as if they were plain files
with size 0, ignoring the link type "1" and hence the link target.

What we should do instead, of course, is to use the link target to get
at the import mark for the contents, even if we cannot recreate the hard
link per se, as Git has no concept of hard links.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
Published-As: https://github.com/dscho/git/releases/tag/import-tars-hardlink-v1
 contrib/fast-import/import-tars.perl | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/contrib/fast-import/import-tars.perl b/contrib/fast-import/import-tars.perl
index 95438e1..d60b431 100755
--- a/contrib/fast-import/import-tars.perl
+++ b/contrib/fast-import/import-tars.perl
@@ -96,18 +96,21 @@ foreach my $tar_file (@ARGV)
 		$mtime = oct $mtime;
 		next if $typeflag == 5; # directory
 
-		print FI "blob\n", "mark :$next_mark\n";
-		if ($typeflag == 2) { # symbolic link
-			print FI "data ", length($linkname), "\n", $linkname;
-			$mode = 0120000;
-		} else {
-			print FI "data $size\n";
-			while ($size > 0 && read(I, $_, 512) == 512) {
-				print FI substr($_, 0, $size);
-				$size -= 512;
+		if ($typeflag != 1) { # handle hard links later
+			print FI "blob\n", "mark :$next_mark\n";
+			if ($typeflag == 2) { # symbolic link
+				print FI "data ", length($linkname), "\n",
+					$linkname;
+				$mode = 0120000;
+			} else {
+				print FI "data $size\n";
+				while ($size > 0 && read(I, $_, 512) == 512) {
+					print FI substr($_, 0, $size);
+					$size -= 512;
+				}
 			}
+			print FI "\n";
 		}
-		print FI "\n";
 
 		my $path;
 		if ($prefix) {
@@ -115,7 +118,13 @@ foreach my $tar_file (@ARGV)
 		} else {
 			$path = "$name";
 		}
-		$files{$path} = [$next_mark++, $mode];
+
+		if ($typeflag == 1) { # hard link
+			$linkname = "$prefix/$linkname" if $prefix;
+			$files{$path} = [ $files{$linkname}->[0], $mode ];
+		} else {
+			$files{$path} = [$next_mark++, $mode];
+		}
 
 		$author_time = $mtime if $mtime > $author_time;
 		$path =~ m,^([^/]+)/,;
-- 
2.9.0.281.g286a8d9

base-commit: f8f7adce9fc50a11a764d57815602dcb818d1816