From 7709acf7beca41be2e382eb0e6c13b5003a20c1a Mon Sep 17 00:00:00 2001 From: Jonathan Tan Date: Mon, 16 May 2022 04:02:20 -0700 Subject: [PATCH] fetch-pack: make unexpected peek result non-fatal When a Git server responds to a fetch request, it may send optional sections before the packfile section. To handle this, the Git client calls packet_reader_peek() (see process_section_header()) in order to see what's next without consuming the line. However, as implemented, Git errors out whenever what's peeked is not an ordinary line. This is not only unexpected (here, we only need to know whether the upcoming line is the section header we want) but causes errors to include the name of a section header that is irrelevant to the cause of the error. For example, at $DAYJOB, we have seen "fatal: error reading section header 'shallow-info'" error messages when none of the repositories involved are shallow. Therefore, fix this so that the peek returns 1 if the upcoming line is the wanted section header and nothing else. Because of this change, reader->line may now be NULL later in the function, so update the error message printing code accordingly. Signed-off-by: Jonathan Tan Signed-off-by: Junio C Hamano --- fetch-pack.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/fetch-pack.c b/fetch-pack.c index dd6ec449f2d..948146b6840 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -1357,17 +1357,20 @@ static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out, static int process_section_header(struct packet_reader *reader, const char *section, int peek) { - int ret; + int ret = 0; - if (packet_reader_peek(reader) != PACKET_READ_NORMAL) - die(_("error reading section header '%s'"), section); - - ret = !strcmp(reader->line, section); + if (packet_reader_peek(reader) == PACKET_READ_NORMAL && + !strcmp(reader->line, section)) + ret = 1; if (!peek) { - if (!ret) - die(_("expected '%s', received '%s'"), - section, reader->line); + if (!ret) { + if (reader->line) + die(_("expected '%s', received '%s'"), + section, reader->line); + else + die(_("expected '%s'"), section); + } packet_reader_read(reader); }