Merge branch 'db/delta-applier' into db/text-delta

* db/delta-applier:
  vcs-svn: cap number of bytes read from sliding view
  test-svn-fe: split off "test-svn-fe -d" into a separate function

4 files changed, 37 insertions, 24 deletions

diff --git a/test-svn-fe.c b/test-svn-fe.c
index 66bd040..332a5f7 100644
--- a/test-svn-fe.c
+++ b/test-svn-fe.c
@@ -8,10 +8,37 @@
 #include "vcs-svn/sliding_window.h"
 #include "vcs-svn/line_buffer.h"
 
+static const char test_svnfe_usage[] =
+	"test-svn-fe (<dumpfile> | [-d] <preimage> <delta> <len>)";
+
+static int apply_delta(int argc, char *argv[])
+{
+	struct line_buffer preimage = LINE_BUFFER_INIT;
+	struct line_buffer delta = LINE_BUFFER_INIT;
+	struct sliding_view preimage_view = SLIDING_VIEW_INIT(&preimage, -1);
+
+	if (argc != 5)
+		usage(test_svnfe_usage);
+
+	if (buffer_init(&preimage, argv[2]))
+		die_errno("cannot open preimage");
+	if (buffer_init(&delta, argv[3]))
+		die_errno("cannot open delta");
+	if (svndiff0_apply(&delta, (off_t) strtoull(argv[4], NULL, 0),
+					&preimage_view, stdout))
+		return 1;
+	if (buffer_deinit(&preimage))
+		die_errno("cannot close preimage");
+	if (buffer_deinit(&delta))
+		die_errno("cannot close delta");
+	buffer_reset(&preimage);
+	strbuf_release(&preimage_view.buf);
+	buffer_reset(&delta);
+	return 0;
+}
+
 int main(int argc, char *argv[])
 {
-	static const char test_svnfe_usage[] =
-		"test-svn-fe (<dumpfile> | [-d] <preimage> <delta> <len>)";
 	if (argc == 2) {
 		if (svndump_init(argv[1]))
 			return 1;
@@ -20,25 +47,8 @@ int main(int argc, char *argv[])
 		svndump_reset();
 		return 0;
 	}
-	if (argc == 5 && !strcmp(argv[1], "-d")) {
-		struct line_buffer preimage = LINE_BUFFER_INIT;
-		struct line_buffer delta = LINE_BUFFER_INIT;
-		struct sliding_view preimage_view = SLIDING_VIEW_INIT(&preimage);
-		if (buffer_init(&preimage, argv[2]))
-			die_errno("cannot open preimage");
-		if (buffer_init(&delta, argv[3]))
-			die_errno("cannot open delta");
-		if (svndiff0_apply(&delta, (off_t) strtoull(argv[4], NULL, 0),
-					&preimage_view, stdout))
-			return 1;
-		if (buffer_deinit(&preimage))
-			die_errno("cannot close preimage");
-		if (buffer_deinit(&delta))
-			die_errno("cannot close delta");
-		buffer_reset(&preimage);
-		strbuf_release(&preimage_view.buf);
-		buffer_reset(&delta);
-		return 0;
-	}
+
+	if (argc >= 2 && !strcmp(argv[1], "-d"))
+		return apply_delta(argc, argv);
 	usage(test_svnfe_usage);
 }
diff --git a/vcs-svn/fast_export.c b/vcs-svn/fast_export.c
index 005674d..edc658d 100644
--- a/vcs-svn/fast_export.c
+++ b/vcs-svn/fast_export.c
@@ -187,7 +187,7 @@ static long apply_delta(off_t len, struct line_buffer *input,
 {
 	long ret;
 	off_t preimage_len = 0;
-	struct sliding_view preimage = SLIDING_VIEW_INIT(&report_buffer);
+	struct sliding_view preimage = SLIDING_VIEW_INIT(&report_buffer, -1);
 	FILE *out;
 
 	if (init_postimage() || !(out = buffer_tmpfile_rewind(&postimage)))
diff --git a/vcs-svn/sliding_window.c b/vcs-svn/sliding_window.c
index 1b8d987..1bac7a4 100644
--- a/vcs-svn/sliding_window.c
+++ b/vcs-svn/sliding_window.c
@@ -54,6 +54,8 @@ int move_window(struct sliding_view *view, off_t off, size_t width)
 		return -1;
 	if (off < view->off || off + width < view->off + view->width)
 		return error("invalid delta: window slides left");
+	if (view->max_off >= 0 && view->max_off < off + width)
+		return error("delta preimage ends early");
 
 	file_offset = view->off + view->buf.len;
 	if (off < file_offset) {
diff --git a/vcs-svn/sliding_window.h b/vcs-svn/sliding_window.h
index ed0bfdd..b43a825 100644
--- a/vcs-svn/sliding_window.h
+++ b/vcs-svn/sliding_window.h
@@ -7,10 +7,11 @@ struct sliding_view {
 	struct line_buffer *file;
 	off_t off;
 	size_t width;
+	off_t max_off;	/* -1 means unlimited */
 	struct strbuf buf;
 };
 
-#define SLIDING_VIEW_INIT(input)	{ (input), 0, 0, STRBUF_INIT }
+#define SLIDING_VIEW_INIT(input, len)	{ (input), 0, 0, (len), STRBUF_INIT }
 
 extern int move_window(struct sliding_view *view, off_t off, size_t width);