correct error messages for NULL packet_read_line()

The packet_read_line() function dies if it gets an unexpected EOF. It only returns NULL if we get a flush packet (or technically, a zero-length "0004" packet, but nobody is supposed to send those, and they are indistinguishable from a flush in this interface). Let's correct error messages which claim an unexpected EOF; it's really an unexpected flush packet. While we're here, let's also check "!line" instead of "!len" in the second case. The two events should always coincide, but checking "!line" makes it more obvious that we are not about to dereference NULL. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Feb 8, 2018 at 13:47 UTC bc9d4dc5b07c05c7b26a4e781b7538db7c775fc3
2 files changed +3 -3
builtin/archive.c
+1 -1
@@ -55,7 +55,7 @@ static int run_remote_archiver(int argc, const char **argv,
55
56 buf = packet_read_line(fd[0], NULL);
57 if (!buf)
58 - die(_("git archive: expected ACK/NAK, got EOF"));
58 + die(_("git archive: expected ACK/NAK, got a flush packet"));
59 if (strcmp(buf, "ACK")) {
60 if (starts_with(buf, "NACK "))
61 die(_("git archive: NACK %s"), buf + 5);
fetch-pack.c
+2 -2
@@ -260,8 +260,8 @@ static enum ack_type get_ack(int fd, struct object_id *result_oid)
260 char *line = packet_read_line(fd, &len);
261 const char *arg;
262
263 - if (!len)
264 - die(_("git fetch-pack: expected ACK/NAK, got EOF"));
263 + if (!line)
264 + die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
265 if (!strcmp(line, "NAK"))
266 return NAK;
267 if (skip_prefix(line, "ACK ", &arg)) {