Allow reading svn dumps from files via file:// urls

For testing as well as for importing large, already available dumps,
it's useful to bypass svnrdump and replay the svndump from a file
directly.

Add support for file:// urls in the remote url, e.g.

  svn::file:///path/to/dump

When the remote helper finds an url starting with file:// it tries to
open that file instead of invoking svnrdump.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

remote-testsvn.c

@@ -9,6 +9,7 @@
 #include "argv-array.h"
 
 static const char *url;
+static int dump_from_file;
 static const char *private_ref;
 static const char *remote_ref = "refs/heads/master";
 
@@ -54,29 +55,36 @@ static int cmd_import(const char *line)
 	struct argv_array svndump_argv = ARGV_ARRAY_INIT;
 	struct child_process svndump_proc;
 
-	memset(&svndump_proc, 0, sizeof(struct child_process));
-	svndump_proc.out = -1;
-	argv_array_push(&svndump_argv, "svnrdump");
-	argv_array_push(&svndump_argv, "dump");
-	argv_array_push(&svndump_argv, url);
-	argv_array_pushf(&svndump_argv, "-r%u:HEAD", startrev);
-	svndump_proc.argv = svndump_argv.argv;
-
-	code = start_command(&svndump_proc);
-	if (code)
-		die("Unable to start %s, code %d", svndump_proc.argv[0], code);
-	dumpin_fd = svndump_proc.out;
-
+	if (dump_from_file) {
+		dumpin_fd = open(url, O_RDONLY);
+		if(dumpin_fd < 0)
+			die_errno("Couldn't open svn dump file %s.", url);
+	} else {
+		memset(&svndump_proc, 0, sizeof(struct child_process));
+		svndump_proc.out = -1;
+		argv_array_push(&svndump_argv, "svnrdump");
+		argv_array_push(&svndump_argv, "dump");
+		argv_array_push(&svndump_argv, url);
+		argv_array_pushf(&svndump_argv, "-r%u:HEAD", startrev);
+		svndump_proc.argv = svndump_argv.argv;
+
+		code = start_command(&svndump_proc);
+		if (code)
+			die("Unable to start %s, code %d", svndump_proc.argv[0], code);
+		dumpin_fd = svndump_proc.out;
+	}
 	svndump_init_fd(dumpin_fd, STDIN_FILENO);
 	svndump_read(url, private_ref);
 	svndump_deinit();
 	svndump_reset();
 
 	close(dumpin_fd);
-	code = finish_command(&svndump_proc);
-	if (code)
-		warning("%s, returned %d", svndump_proc.argv[0], code);
-	argv_array_clear(&svndump_argv);
+	if (!dump_from_file) {
+		code = finish_command(&svndump_proc);
+		if (code)
+			warning("%s, returned %d", svndump_proc.argv[0], code);
+		argv_array_clear(&svndump_argv);
+	}
 
 	return 0;
 }
@@ -151,8 +159,14 @@ int main(int argc, const char **argv)
 	remote = remote_get(argv[1]);
 	url_in = (argc == 3) ? argv[2] : remote->url[0];
 
-	end_url_with_slash(&url_sb, url_in);
-	url = url_sb.buf;
+	if (!prefixcmp(url_in, "file://")) {
+		dump_from_file = 1;
+		url = url_decode(url_in + sizeof("file://")-1);
+	} else {
+		dump_from_file = 0;
+		end_url_with_slash(&url_sb, url_in);
+		url = url_sb.buf;
+	}
 
 	strbuf_addf(&private_ref_sb, "refs/svn/%s/master", remote->name);
 	private_ref = private_ref_sb.buf;