write-tree: --prefix=<path>

The "bind" commit can express an aggregation of multiple
projects into a single commit.

In such an organization, there would be one project, root of
whose tree object is at the same level of the root of the
aggregated projects, and other projects have their toplevel in
separate subdirectories.  Let's call that root level project the
"primary project", and call other ones just "subprojects".

You would first read-tree the primary project, and then graft
the subprojects under their appropriate location using read-tree
--prefix=<subdir>/ repeatedly.

To write out a tree object from such an index for a subproject,
write-tree --prefix=<subdir>/ is used.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 14 insertions, 0 deletions

diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index cf33989b56..2c9bbb59b0 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -195,6 +195,20 @@ test_expect_success \
     'git-ls-tree -r output for a known tree.' \
     'diff current expected'
 
+test_expect_success \
+    'writing partial tree out with git-write-tree --prefix.' \
+    'ptree=$(git-write-tree --prefix=path3)'
+test_expect_success \
+    'validate object ID for a known tree.' \
+    'test "$ptree" = 21ae8269cacbe57ae09138dcc3a2887f904d02b3'
+
+test_expect_success \
+    'writing partial tree out with git-write-tree --prefix.' \
+    'ptree=$(git-write-tree --prefix=path3/subp3)'
+test_expect_success \
+    'validate object ID for a known tree.' \
+    'test "$ptree" = 3c5e5399f3a333eddecce7a9b9465b63f65f51e2'
+
 ################################################################
 rm .git/index
 test_expect_success \