vcs-svn: set up channel to read fast-import cat-blob response

Set up some plumbing: teach the svndump lib to pass a file descriptor
number to the fast_export lib, representing where cat-blob/ls
responses can be read from, and add a get_response_line helper
function to the fast_export lib to read a line from that file.

Unfortunately this means that svn-fe needs file descriptor 3 to be
redirected from somewhere (preferrably the cat-blob stream of a
fast-import backend); otherwise it will fail:

	$ svndump <path> | svn-fe
	fatal: cannot read from file descriptor 3: Bad file descriptor

For the moment, "svn-fe 3</dev/null" works as a workaround but it
will not work for very long.  A fast-import backend that can retrieve
old commits is needed in order to be able to fulfill svn
"Node-copyfrom-rev" requests that refer to revs from a previous run.

[jn: with new change description]

Based-on-patch-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/vcs-svn/fast_export.h b/vcs-svn/fast_export.h
index 054e7d5eb1..fed30c14e6 100644
--- a/vcs-svn/fast_export.h
+++ b/vcs-svn/fast_export.h
@@ -3,6 +3,10 @@
 
 #include "line_buffer.h"
 
+void fast_export_init(int fd);
+void fast_export_deinit(void);
+void fast_export_reset(void);
+
 void fast_export_delete(uint32_t depth, uint32_t *path);
 void fast_export_modify(uint32_t depth, uint32_t *path, uint32_t mode,
 			uint32_t mark);