svn symlinks are files with "link destination" content and a
"svn:special=*" property set. These are imported as blobs with
"destination" content and S_IFLNK mode. When svn copy a file without
altering it's content(but maybe altering it's mode), we reuse the blob
object thus loosing or not adding the "link " prefix.
But we take possible prefix into account when applying svn deltas. And
this is the only place we ask fast-import for original blob. So pretend
that we want to apply a zero delta to resolve the issue.
There is some overhead due to using a temporary file to store such a small
blob. But hopefully such node change is too rare to care.
Signed-off-by: Dmitry Ivankov <divanorama@xxxxxxxxx>
---
This could be done better if we just read the cat-blob to memory, added or
removed the "link " prefix and wrote it to the stream, because the link
destination should be a tiny string. But on the other hand it'd blow up
if for some reason it's huge.
And taking into account that changing file mode from/to link without a
content change should be extremely rare anyway, I think it's ok.
Maybe it is redundant to add svndiff0_identity function to just cat blob
to a temporary file. The excuse is that svndiff.c is the only user of this
temporary file and the cat-blob response, so keep it there.
The patch base is svn-fe branch at git://repo.or.cz/git/jrn.git
Not backporting it to git master because vcs-svn stuff differs quite much
around this change.
t/t9010-svn-fe.sh | 2 +-
vcs-svn/fast_export.c | 6 +++++-
vcs-svn/svndiff.c | 17 +++++++++++++++++
vcs-svn/svndiff.h | 1 +
vcs-svn/svndump.c | 16 +++++++++++++++-
5 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/t/t9010-svn-fe.sh b/t/t9010-svn-fe.sh
index b7eed24..b6bdfeb 100755
--- a/t/t9010-svn-fe.sh
+++ b/t/t9010-svn-fe.sh
@@ -413,7 +413,7 @@ test_expect_success PIPE 'action: add node without text' '
try_dump textless.dump must_fail
'
-test_expect_failure PIPE 'change file mode but keep old content' '
+test_expect_success PIPE 'change file mode but keep old content' '
reinit_git &&
cat >expect <<-\EOF &&
OBJID
diff --git a/vcs-svn/fast_export.c b/vcs-svn/fast_export.c
index 19d7c34..8c7295f 100644
--- a/vcs-svn/fast_export.c
+++ b/vcs-svn/fast_export.c
@@ -209,7 +209,11 @@ static long apply_delta(off_t len, struct line_buffer *input,
preimage.max_off += strlen("link ");
check_preimage_overflow(preimage.max_off, 1);
}
- if (svndiff0_apply(input, len, &preimage, out))
+
+ if (!input) {
+ if (svndiff0_identity(&preimage, out))
+ die("cannot cat blob");
+ } else if (svndiff0_apply(input, len, &preimage, out))
die("cannot apply delta");
if (old_data) {
/* Read the remainder of preimage and trailing newline. */
diff --git a/vcs-svn/svndiff.c b/vcs-svn/svndiff.c
index 9ee41bb..bf104db 100644
--- a/vcs-svn/svndiff.c
+++ b/vcs-svn/svndiff.c
@@ -306,3 +306,20 @@ int svndiff0_apply(struct line_buffer *delta, off_t delta_len,
}
return 0;
}
+int svndiff0_identity(struct sliding_view *preimage, FILE *postimage)
+{
+ assert(preimage && postimage);
+ off_t pre_off = 0;
+
+ while (pre_off != preimage->max_off) {
+ size_t pre_len = 8192;
+ if (pre_off + pre_len > preimage->max_off)
+ pre_len = preimage->max_off - pre_off;
+ if (move_window(preimage, pre_off, pre_len) ||
+ write_strbuf(&preimage->buf, postimage))
+ return -1;
+ pre_off += pre_len;
+ }
+
+ return 0;
+}
diff --git a/vcs-svn/svndiff.h b/vcs-svn/svndiff.h
index 74eb464..5afa3f2 100644
--- a/vcs-svn/svndiff.h
+++ b/vcs-svn/svndiff.h
@@ -6,5 +6,6 @@ struct sliding_view;
extern int svndiff0_apply(struct line_buffer *delta, off_t delta_len,
struct sliding_view *preimage, FILE *postimage);
+extern int svndiff0_identity(struct sliding_view *preimage, FILE *postimage);
#endif
diff --git a/vcs-svn/svndump.c b/vcs-svn/svndump.c
index b1f4161..1e7ed48 100644
--- a/vcs-svn/svndump.c
+++ b/vcs-svn/svndump.c
@@ -285,7 +285,21 @@ static void handle_node(void)
/* For the fast_export_* functions, NULL means empty. */
old_data = NULL;
if (!have_text) {
- fast_export_modify(node_ctx.dst.buf, node_ctx.type, old_data);
+ /*
+ * This is clean content copy in svn, but we alter the content
+ * of symlinks (add/remove "link " prefix used by svn). So when
+ * mode changes from/to symlink specify (recreate) data inline.
+ */
+ if (node_ctx.type != old_mode && (old_mode == REPO_MODE_LNK
+ || node_ctx.type == REPO_MODE_LNK)) {
+
+ fast_export_modify(node_ctx.dst.buf,
+ node_ctx.type, "inline");
+ fast_export_blob_delta(node_ctx.type, old_mode,
+ old_data, 0, NULL);
+ } else
+ fast_export_modify(node_ctx.dst.buf,
+ node_ctx.type, old_data);
return;
}
if (!node_ctx.text_delta) {
--
1.7.3.4
--
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