Merge branch 'lt/refs' into jc/lt-ref2-with-lt-refs

* lt/refs: (58 commits)
  git-pack-refs --prune
  pack-refs: do not pack symbolic refs.
  Tell between packed, unpacked and symbolic refs.
  Add callback data to for_each_ref() family.
  symbolit-ref: fix resolve_ref conversion.
  Fix broken sha1 locking
  fsck-objects: adjust to resolve_ref() clean-up.
  gitignore: git-pack-refs is a generated file.
  wt-status: use simplified resolve_ref to find current branch
  Fix t1400-update-ref test minimally
  Enable the packed refs file format
  Make ref resolution saner
  Add support for negative refs
  Start handling references internally as a sorted in-memory list
  gitweb fix validating pg (page) parameter
  git-repack(1): document --window and --depth
  git-apply(1): document --unidiff-zero
  gitweb: fix warnings in PATH_INFO code and add export_ok/strict_export
  upload-archive: monitor child communication even more carefully.
  gitweb: export options
  ...

1 files changed, 74 insertions, 0 deletions

diff --git a/sideband.c b/sideband.c
new file mode 100644
index 0000000000..1b14ff8892
--- /dev/null
+++ b/sideband.c
@@ -0,0 +1,74 @@
+#include "pkt-line.h"
+#include "sideband.h"
+
+/*
+ * Receive multiplexed output stream over git native protocol.
+ * in_stream is the input stream from the remote, which carries data
+ * in pkt_line format with band designator.  Demultiplex it into out
+ * and err and return error appropriately.  Band #1 carries the
+ * primary payload.  Things coming over band #2 is not necessarily
+ * error; they are usually informative message on the standard error
+ * stream, aka "verbose").  A message over band #3 is a signal that
+ * the remote died unexpectedly.  A flush() concludes the stream.
+ */
+int recv_sideband(const char *me, int in_stream, int out, int err, char *buf, int bufsz)
+{
+	while (1) {
+		int len = packet_read_line(in_stream, buf, bufsz);
+		if (len == 0)
+			break;
+		if (len < 1) {
+			len = sprintf(buf, "%s: protocol error: no band designator\n", me);
+			safe_write(err, buf, len);
+			return SIDEBAND_PROTOCOL_ERROR;
+		}
+		len--;
+		switch (buf[0] & 0xFF) {
+		case 3:
+			safe_write(err, "remote: ", 8);
+			safe_write(err, buf+1, len);
+			safe_write(err, "\n", 1);
+			return SIDEBAND_REMOTE_ERROR;
+		case 2:
+			safe_write(err, "remote: ", 8);
+			safe_write(err, buf+1, len);
+			continue;
+		case 1:
+			safe_write(out, buf+1, len);
+			continue;
+		default:
+			len = sprintf(buf + 1,
+				      "%s: protocol error: bad band #%d\n",
+				      me, buf[0] & 0xFF);
+			safe_write(err, buf+1, len);
+			return SIDEBAND_PROTOCOL_ERROR;
+		}
+	}
+	return 0;
+}
+
+/*
+ * fd is connected to the remote side; send the sideband data
+ * over multiplexed packet stream.
+ */
+ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
+{
+	ssize_t ssz = sz;
+	const char *p = data;
+
+	while (sz) {
+		unsigned n;
+		char hdr[5];
+
+		n = sz;
+		if (packet_max - 5 < n)
+			n = packet_max - 5;
+		sprintf(hdr, "%04x", n + 5);
+		hdr[4] = band;
+		safe_write(fd, hdr, 5);
+		safe_write(fd, p, n);
+		p += n;
+		sz -= n;
+	}
+	return ssz;
+}