merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 0 insertions, 79 deletions

diff --git a/third_party/git/vcs-svn/sliding_window.c b/third_party/git/vcs-svn/sliding_window.c
deleted file mode 100644
index 06d273c9e8ce..000000000000
--- a/third_party/git/vcs-svn/sliding_window.c
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Licensed under a two-clause BSD-style license.
- * See LICENSE for details.
- */
-
-#include "git-compat-util.h"
-#include "sliding_window.h"
-#include "line_buffer.h"
-#include "strbuf.h"
-
-static int input_error(struct line_buffer *file)
-{
-	if (!buffer_ferror(file))
-		return error("delta preimage ends early");
-	return error_errno("cannot read delta preimage");
-}
-
-static int skip_or_whine(struct line_buffer *file, off_t gap)
-{
-	if (buffer_skip_bytes(file, gap) != gap)
-		return input_error(file);
-	return 0;
-}
-
-static int read_to_fill_or_whine(struct line_buffer *file,
-				struct strbuf *buf, size_t width)
-{
-	buffer_read_binary(file, buf, width - buf->len);
-	if (buf->len != width)
-		return input_error(file);
-	return 0;
-}
-
-static int check_offset_overflow(off_t offset, uintmax_t len)
-{
-	if (len > maximum_signed_value_of_type(off_t))
-		return error("unrepresentable length in delta: "
-				"%"PRIuMAX" > OFF_MAX", len);
-	if (signed_add_overflows(offset, (off_t) len))
-		return error("unrepresentable offset in delta: "
-				"%"PRIuMAX" + %"PRIuMAX" > OFF_MAX",
-				(uintmax_t) offset, len);
-	return 0;
-}
-
-int move_window(struct sliding_view *view, off_t off, size_t width)
-{
-	off_t file_offset;
-	assert(view);
-	assert(view->width <= view->buf.len);
-	assert(!check_offset_overflow(view->off, view->buf.len));
-
-	if (check_offset_overflow(off, 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 + (off_t) width)
-		return error("delta preimage ends early");
-
-	file_offset = view->off + view->buf.len;
-	if (off < file_offset) {
-		/* Move the overlapping region into place. */
-		strbuf_remove(&view->buf, 0, off - view->off);
-	} else {
-		/* Seek ahead to skip the gap. */
-		if (skip_or_whine(view->file, off - file_offset))
-			return -1;
-		strbuf_setlen(&view->buf, 0);
-	}
-
-	if (view->buf.len > width)
-		; /* Already read. */
-	else if (read_to_fill_or_whine(view->file, &view->buf, width))
-		return -1;
-
-	view->off = off;
-	view->width = width;
-	return 0;
-}