From cfbdef424610ed377d10b3d33e1ae01bbe3d631b Mon Sep 17 00:00:00 2001
From: Oleg Pykhalov <address@hidden>
Date: Thu, 1 Feb 2018 10:25:00 +0300
Subject: [PATCH 1/2] VC.pm: also work in a git "worktree"

* VC.pm (new): Also accept a ".git" file, which is what you
get in a git worktree.
---
 VC.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/VC.pm b/VC.pm
index 4252c61..2c7acbc 100644
--- a/VC.pm
+++ b/VC.pm
@@ -132,7 +132,7 @@ sub new($%)
 	  }
 	}

-      if (-d "$d/.git/objects") {
+      if (-d "$d/.git/objects" || -f "$d/.git") {
 	$self->{name} = GIT;
       } elsif (-d "$d/.bzr/repository") {
 	$self->{name} = BZR;
-- 
2.15.1.433.g936d1b989


From 037883d4d1f17561da7747684edccfd6154b1d73 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sun, 4 Feb 2018 01:58:49 -0800
Subject: [PATCH 2/2] vc-dwim: also work with a git worktree

* vc-dwim.pl (admin_dir): Also handle the case in which .git
is a file, as it is for a git worktree.
* tests/git-worktree: New file.
* tests/Makefile.am (TESTS): Add it.
* NEWS: Mention the fix.
---
 NEWS               |  1 +
 tests/Makefile.am  |  1 +
 tests/git-worktree | 20 ++++++++++++++++++++
 vc-dwim.pl         | 15 ++++++++++++++-
 4 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100755 tests/git-worktree

diff --git a/NEWS b/NEWS
index de4c77c..91309b5 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,7 @@ vc-dwim NEWS                                          -*- outline -*-

 * Noteworthy changes in release ?.? (????-??-??) [?]

+  vc-dwim and vc-chlog now also work with git worktree directories

 * Noteworthy changes in release 1.8 (2017-01-14) [stable]

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 457cc0f..c0a6549 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -14,6 +14,7 @@ TESTS = \
   subdir-middle \
   add-empty \
   git-mv \
+  git-worktree \
   two-line-attr \
   cl-other-user \
   cl-syntax \
diff --git a/tests/git-worktree b/tests/git-worktree
new file mode 100755
index 0000000..0104d4b
--- /dev/null
+++ b/tests/git-worktree
@@ -0,0 +1,20 @@
+#!/bin/sh
+# Ensure things work in a git worktree, for which .git is a file.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ..
+print_ver_ vc-dwim
+
+require_git_
+
+git init > /dev/null			\
+  && touch x				\
+  && git add .				\
+  && git commit -m m . > /dev/null	\
+  && git worktree add wt		\
+  && cd wt				\
+    || framework_failure_
+
+fail=0
+vc-dwim --init || fail=1
+
+Exit $fail
diff --git a/vc-dwim.pl b/vc-dwim.pl
index c869319..5dbbdab 100755
--- a/vc-dwim.pl
+++ b/vc-dwim.pl
@@ -690,11 +690,24 @@ sub check_attribution($$)
     or die "$ME: --author/ChangeLog mismatch:\n  $$author\n  $name_and_email\n";
 }

-# Return the name of the/an admin directory residing in
+# Return the name of the/an admin directory associated with
 # the current directory.  If there is none, return undef.
 sub admin_dir()
 {
+  # This is the usual case: a .git directory.
   -d '.git/objects' and return '.git';
+  # With a git worktree, .git is a file containing a line of this form:
+  # gitdir: /abs/dir
+  my $git_file = '.git';
+  if (-f $git_file)
+    {
+      # Read .git, and extract the name after "gitdir: "
+      my $fh = new IO::File $git_file, 'r'
+        or die "$ME: can't open `$git_file' for reading: $!\n";
+      my $line = <$fh>;
+      defined $line && $line =~ /^gitdir: (.+)$/
+        and return $1;
+    }
   -d '.hg' and return '.hg';
   -d 'CVS' and return 'CVS';
   -d '.svn' and return '.svn';
-- 
2.15.1.433.g936d1b989