[PATCH] git-subtree: compare file names by absolute paths

This commit removes false positive assertion fails of `git subtree split` when
the --prefix argument is not in a particular form produced by `git ls-tree`.

For example, typical usage of the command could be:

  git subtree split -b split --prefix=some/relative/path

But

  git subtree split -b split --prefix=./some/relative/path

Would fail with multiple assertion errors. This commit makes the latter command
work without errors.

Signed-off-by: Ivan Oleynikov <redacted>
---

Notes:
    The bug fixed by this commit can be reproduced like this:
    
    $ git init
    Initialized empty Git repository in /tmp/test/.git/
    $ mkdir a b
    $ touch a/file b/file
    $ git add a
    $ git commit -m a
    [master (root-commit) b42584a] a
     1 file changed, 0 insertions($), 0 deletions(-)
     create mode 100644 a/file
    $ git add b
    $ git commit -m b
    [master 5114301] b
     1 file changed, 0 insertions($), 0 deletions(-)
     create mode 100644 b/file
    $ git subtree split -b split_a --prefix=a
    Created branch 'split_a'
    e9f5d81efacb33ab6cf67fe9ff376b33a483a92f
    $ git subtree split -b split_b --prefix=./b
    assertion failed:  [ b = ./b ]
    No new revisions were found
    
    When the commit is applied `git subtree split` works as expected:
    
    $ git init
    Initialized empty Git repository in /tmp/test/.git/
    $ mkdir a b
    $ touch a/file b/file
    $ git add a
    $ git commit -m a
    [master (root-commit) bc80f36] a
     1 file changed, 0 insertions($), 0 deletions(-)
     create mode 100644 a/file
    $ git add b
    $ git commit -m b
    [master e59c446] b
     1 file changed, 0 insertions($), 0 deletions(-)
     create mode 100644 b/file
    $ git subtree split -b split_a --prefix=a
    Created branch 'split_a'
    d542e9cd2de5956dd7ca77b169dba1c8418fa03a
    $ git subtree split -b split_b --prefix=./b
    Created branch 'split_b'
    3ae7854c0c395413c807b2bc4e75b651adc63f8c

 contrib/subtree/git-subtree.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index b567eae..d9351b9 100755
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh

@@ -411,7 +411,7 @@ subtree_for_commit()
 	dir="$2"
 	git ls-tree "$commit" -- "$dir" |
 	while read mode type tree name; do
-		assert [ "$name" = "$dir" ]
+		assert [ "$(readlink -f $name)" = "$(readlink -f $dir)" ]
 		assert [ "$type" = "tree" -o "$type" = "commit" ]
 		[ "$type" = "commit" ] && continue  # ignore submodules
 		echo $tree

-- 
2.1.4


-- 
Ivan Oleynikov
STC Metrotek
St.Petersburg

quote on Fri, Aug 12, 2016 at 06:49:42PM +0300 (Ivan Oleynikov):

BTW, this patch should be applied to `maint` branch. The similar change also
works if applied to master (patch for master must be a bit different).

-- 
Ivan Oleynikov
STC Metrotek
St.Petersburg