recv_sideband: Bands #2 and #3 always go to stderr

This removes the last parameter of recv_sideband, by which the callers
told which channel bands #2 and #3 should be written to.

Sayeth Shawn Pearce:

   The definition of the streams in the current sideband protocol
   are rather well defined for the one protocol that uses it,
   fetch-pack/receive-pack:

     stream #1:  pack data
     stream #2:  stderr messages, progress, meant for tty
     stream #3:  abort message, remote is dead, goodbye!

Since both callers of the function passed 2 for the parameter, we hereby
remove it and send bands #2 and #3 to stderr explicitly using fprintf.

This has the nice side-effect that these two streams pass through our
ANSI emulation layer on Windows.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-archive.c

@@ -52,7 +52,7 @@ static int run_remote_archiver(int argc, const char **argv,
 		die("git archive: expected a flush");
 
 	/* Now, start reading from fd[0] and spit it out to stdout */
-	rv = recv_sideband("archive", fd[0], 1, 2);
+	rv = recv_sideband("archive", fd[0], 1);
 	close(fd[0]);
 	close(fd[1]);
 	rv |= finish_connect(conn);

builtin-fetch-pack.c

@@ -482,7 +482,7 @@ static int sideband_demux(int fd, void *data)
 {
 	int *xd = data;
 
-	return recv_sideband("fetch-pack", xd[0], fd, 2);
+	return recv_sideband("fetch-pack", xd[0], fd);
 }
 
 static int get_pack(int xd[2], char **pack_lockfile)

sideband.c

@@ -19,7 +19,7 @@
 
 #define FIX_SIZE 10  /* large enough for any of the above */
 
-int recv_sideband(const char *me, int in_stream, int out, int err)
+int recv_sideband(const char *me, int in_stream, int out)
 {
 	unsigned pf = strlen(PREFIX);
 	unsigned sf;
@@ -41,17 +41,16 @@ int recv_sideband(const char *me, int in_stream, int out, int err)
 		if (len == 0)
 			break;
 		if (len < 1) {
-			len = sprintf(buf, "%s: protocol error: no band designator\n", me);
-			safe_write(err, buf, len);
+			fprintf(stderr, "%s: protocol error: no band designator\n", me);
 			return SIDEBAND_PROTOCOL_ERROR;
 		}
 		band = buf[pf] & 0xff;
 		len--;
 		switch (band) {
 		case 3:
 			buf[pf] = ' ';
-			buf[pf+1+len] = '\n';
-			safe_write(err, buf, pf+1+len+1);
+			buf[pf+1+len] = '\0';
+			fprintf(stderr, "%s\n", buf);
 			return SIDEBAND_REMOTE_ERROR;
 		case 2:
 			buf[pf] = ' ';
@@ -95,12 +94,12 @@ int recv_sideband(const char *me, int in_stream, int out, int err)
 					memcpy(save, b + brk, sf);
 					b[brk + sf - 1] = b[brk - 1];
 					memcpy(b + brk - 1, suffix, sf);
-					safe_write(err, b, brk + sf);
+					fprintf(stderr, "%.*s", brk + sf, b);
 					memcpy(b + brk, save, sf);
 					len -= brk;
 				} else {
 					int l = brk ? brk : len;
-					safe_write(err, b, l);
+					fprintf(stderr, "%.*s", l, b);
 					len -= l;
 				}
 
@@ -112,10 +111,8 @@ int recv_sideband(const char *me, int in_stream, int out, int err)
 			safe_write(out, buf + pf+1, len);
 			continue;
 		default:
-			len = sprintf(buf,
-				      "%s: protocol error: bad band #%d\n",
-				      me, band);
-			safe_write(err, buf, len);
+			fprintf(stderr, "%s: protocol error: bad band #%d\n",
+				me, band);
 			return SIDEBAND_PROTOCOL_ERROR;
 		}
 	}

sideband.h

@@ -7,7 +7,7 @@
 #define DEFAULT_PACKET_MAX 1000
 #define LARGE_PACKET_MAX 65520
 
-int recv_sideband(const char *me, int in_stream, int out, int err);
+int recv_sideband(const char *me, int in_stream, int out);
 ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max);
 
 #endif