On 09/26, Jonathan Tan wrote:
> Currently, get_remote_heads() parses the ref advertisement in one loop,
> allowing refs and shallow lines to intersperse, despite this not being
> allowed by the specification. Refactor get_remote_heads() to use two
> loops instead, enforcing that refs come first, and then shallows.
>
> This also makes it easier to teach get_remote_heads() to interpret other
> lines in the ref advertisement, which will be done in a subsequent
> patch.
>
> As part of this change, this patch interprets capabilities only on the
> first line in the ref advertisement, printing a warning message when
> encountering capabilities on other lines.
>
> Signed-off-by: Jonathan Tan
> ---
> Changes in v5:
> - print warning when encountering capabilities on other lines instead
>of ignoring them (also updated commit message)
> - explicitly disallow refs of name "capabilities^{}" (except when it is
>the only ref)
> ---
> connect.c | 183
> +++---
> 1 file changed, 117 insertions(+), 66 deletions(-)
>
> diff --git a/connect.c b/connect.c
> index df56c0cbf..df65a3fc4 100644
> --- a/connect.c
> +++ b/connect.c
> @@ -11,6 +11,7 @@
> #include "string-list.h"
> #include "sha1-array.h"
> #include "transport.h"
> +#include "strbuf.h"
>
> static char *server_capabilities;
> static const char *parse_feature_value(const char *, const char *, int *);
> @@ -107,6 +108,98 @@ static void annotate_refs_with_symref_info(struct ref
> *ref)
> string_list_clear(, 0);
> }
>
> +/*
> + * Read one line of a server's ref advertisement into packet_buffer.
> + */
> +static int read_remote_ref(int in, char **src_buf, size_t *src_len,
> +int *responded)
> +{
> + int len = packet_read(in, src_buf, src_len,
> + packet_buffer, sizeof(packet_buffer),
> + PACKET_READ_GENTLE_ON_EOF |
> + PACKET_READ_CHOMP_NEWLINE);
> + const char *arg;
> + if (len < 0)
> + die_initial_contact(*responded);
> + if (len > 4 && skip_prefix(packet_buffer, "ERR ", ))
> + die("remote error: %s", arg);
> +
> + *responded = 1;
> +
> + return len;
> +}
> +
> +#define EXPECTING_FIRST_REF 0
> +#define EXPECTING_REF 1
> +#define EXPECTING_SHALLOW 2
> +
> +static void process_capabilities(int *len)
> +{
> + int nul_location = strlen(packet_buffer);
> + if (nul_location == *len)
> + return;
> + server_capabilities = xstrdup(packet_buffer + nul_location + 1);
> + *len = nul_location;
> +}
> +
> +static int process_dummy_ref(void)
> +{
> + static char *template;
> + if (!template)
> + template = xstrfmt("%040d capabilities^{}", 0);
My only complaint is still here, I don't like the notion of hardcoding
the 0's. Its much more future proof and less error prone to call
parse_oid_hex and require that it matches null_oid.
> + return !strcmp(packet_buffer, template);
> +}
> +
> +static void check_no_capabilities(int len)
> +{
> + if (strlen(packet_buffer) != len)
> + warning("Ignoring capabilities after first line '%s'",
> + packet_buffer + strlen(packet_buffer));
> +}
> +
> +static int process_ref(int len, struct ref ***list, unsigned int flags,
> +struct oid_array *extra_have)
> +{
> + struct object_id old_oid;
> + const char *name;
> +
> + if (parse_oid_hex(packet_buffer, _oid, ))
> + return 0;
> + if (*name != ' ')
> + return 0;
> + name++;
> +
> + if (extra_have && !strcmp(name, ".have")) {
> + oid_array_append(extra_have, _oid);
> + } else if (!strcmp(name, "capabilities^{}")) {
> + die("protocol error: unexpected capabilities^{}");
> + } else if (check_ref(name, flags)) {
> + struct ref *ref = alloc_ref(name);
> + oidcpy(>old_oid, _oid);
> + **list = ref;
> + *list = >next;
> + }
> + check_no_capabilities(len);
> + return 1;
> +}
> +
> +static int process_shallow(int len, struct oid_array *shallow_points)
> +{
> + const char *arg;
> + struct object_id old_oid;
> +
> + if (!skip_prefix(packet_buffer, "shallow ", ))
> + return 0;
> +
> + if (get_oid_hex(arg, _oid))
> + die("protocol error: expected shallow sha-1, got '%s'", arg);
> + if (!shallow_points)
> + die("repository on the other end cannot be shallow");
> + oid_array_append(shallow_points, _oid);
> + check_no_capabilities(len);
> + return 1;
> +}
> +
> /*
> * Read all the refs from the other end
> */
> @@ -123,76 +216,34 @@ struct ref **get_remote_heads(int in, char *src_buf,
> size_t src_len,
>* willing to talk to us. A hang-up before seeing any
>* response does not necessarily mean an ACL problem, though.
>*/
> -