fast-import: treat filemodify with empty tree as delete

Normal git processes do not allow one to build a tree with an empty
subtree entry without trying hard at it.  This is in keeping with the
general UI philosophy: git tracks content, not empty directories.

v1.7.3-rc0~75^2 (2010-06-30) changed that by making it easy to include
an empty subtree in fast-import's active commit:

	M 040000 4b825dc642cb6eb9a060e54bf8d69288fbee4904 subdir

One can trigger this by reading an empty tree (for example, the tree
corresponding to an empty root commit) and trying to move it to a
subtree.  It is better and more closely analogous to 'git read-tree
--prefix' to treat such commands as requests to remove the subtree.

Noticed-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/fast-import.c b/fast-import.c
index ad6843a8b6cf0a59466a87a89a90165751923273..cd9310d1e5a5ac0cc6edf83c93c5f254fd579f64 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -2163,6 +2163,12 @@ static void file_change_m(struct branch *b)
                p = uq.buf;
        }
 
+       /* Git does not track empty, non-toplevel directories. */
+       if (S_ISDIR(mode) && !memcmp(sha1, EMPTY_TREE_SHA1_BIN, 20) && *p) {
+               tree_content_remove(&b->branch_tree, p, NULL);
+               return;
+       }
+
        if (S_ISGITLINK(mode)) {
                if (inline_data)
                        die("Git links cannot be specified 'inline': %s",

diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 50d5913cc12ae5e67ec5b99cd001a7adf106ee4f..8487734ada77b4667c89665d255886c59cff8b22 100755 (executable)
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -817,6 +817,48 @@ test_expect_success \
         git diff-tree -C --find-copies-harder -r N4^ N4 >actual &&
         compare_diff_raw expect actual'
 
+test_expect_success \
+       'N: delete directory by copying' \
+       'cat >expect <<-\EOF &&
+       OBJID
+       :100644 000000 OBJID OBJID D    foo/bar/qux
+       OBJID
+       :000000 100644 OBJID OBJID A    foo/bar/baz
+       :000000 100644 OBJID OBJID A    foo/bar/qux
+       EOF
+        empty_tree=$(git mktree </dev/null) &&
+        cat >input <<-INPUT_END &&
+       commit refs/heads/N-delete
+       committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+       data <<COMMIT
+       collect data to be deleted
+       COMMIT
+
+       deleteall
+       M 100644 inline foo/bar/baz
+       data <<DATA_END
+       hello
+       DATA_END
+       C "foo/bar/baz" "foo/bar/qux"
+       C "foo/bar/baz" "foo/bar/quux/1"
+       C "foo/bar/baz" "foo/bar/quuux"
+       M 040000 $empty_tree foo/bar/quux
+       M 040000 $empty_tree foo/bar/quuux
+
+       commit refs/heads/N-delete
+       committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+       data <<COMMIT
+       delete subdirectory
+       COMMIT
+
+       M 040000 $empty_tree foo/bar/qux
+       INPUT_END
+        git fast-import <input &&
+        git rev-list N-delete |
+               git diff-tree -r --stdin --root --always |
+               sed -e "s/$_x40/OBJID/g" >actual &&
+        test_cmp expect actual'
+
 test_expect_success \
        'N: modify copied tree' \
        'cat >expect <<-\EOF &&