Merge branch 'jc/capabilities' into maint

* jc/capabilities:
  fetch-pack: mention server version with verbose output
  parse_feature_request: make it easier to see feature values
  fetch-pack: do not ask for unadvertised capabilities
  do not send client agent unless server does first
  send-pack: fix capability-sending logic
  include agent identifier in capability string

8 files changed, 102 insertions, 17 deletions

diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 149db88726..fdda36f149 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -10,6 +10,7 @@
 #include "remote.h"
 #include "run-command.h"
 #include "transport.h"
+#include "version.h"
 
 static int transfer_unpack_limit = -1;
 static int fetch_unpack_limit = -1;
@@ -18,6 +19,7 @@ static int prefer_ofs_delta = 1;
 static int no_done;
 static int fetch_fsck_objects = -1;
 static int transfer_fsck_objects = -1;
+static int agent_supported;
 static struct fetch_pack_args args = {
 	/* .uploadpack = */ "git-upload-pack",
 };
@@ -327,6 +329,8 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 			if (args.no_progress)   strbuf_addstr(&c, " no-progress");
 			if (args.include_tag)   strbuf_addstr(&c, " include-tag");
 			if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
+			if (agent_supported)    strbuf_addf(&c, " agent=%s",
+							    git_user_agent_sanitized());
 			packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 			strbuf_release(&c);
 		} else
@@ -783,6 +787,8 @@ static struct ref *do_fetch_pack(int fd[2],
 {
 	struct ref *ref = copy_ref_list(orig_ref);
 	unsigned char sha1[20];
+	const char *agent_feature;
+	int agent_len;
 
 	sort_ref_list(&ref, ref_compare_name);
 
@@ -814,11 +820,25 @@ static struct ref *do_fetch_pack(int fd[2],
 			fprintf(stderr, "Server supports side-band\n");
 		use_sideband = 1;
 	}
+	if (!server_supports("thin-pack"))
+		args.use_thin_pack = 0;
+	if (!server_supports("no-progress"))
+		args.no_progress = 0;
+	if (!server_supports("include-tag"))
+		args.include_tag = 0;
 	if (server_supports("ofs-delta")) {
 		if (args.verbose)
 			fprintf(stderr, "Server supports ofs-delta\n");
 	} else
 		prefer_ofs_delta = 0;
+
+	if ((agent_feature = server_feature_value("agent", &agent_len))) {
+		agent_supported = 1;
+		if (args.verbose && agent_len)
+			fprintf(stderr, "Server version is %.*s\n",
+				agent_len, agent_feature);
+	}
+
 	if (everything_local(&ref, nr_match, match)) {
 		packet_flush(fd[1]);
 		goto all_done;
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 3f05d971ec..2cb854feb4 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -12,6 +12,7 @@
 #include "string-list.h"
 #include "sha1-array.h"
 #include "connected.h"
+#include "version.h"
 
 static const char receive_pack_usage[] = "git receive-pack <git-dir>";
 
@@ -121,10 +122,11 @@ static void show_ref(const char *path, const unsigned char *sha1)
 	if (sent_capabilities)
 		packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
 	else
-		packet_write(1, "%s %s%c%s%s\n",
+		packet_write(1, "%s %s%c%s%s agent=%s\n",
 			     sha1_to_hex(sha1), path, 0,
 			     " report-status delete-refs side-band-64k quiet",
-			     prefer_ofs_delta ? " ofs-delta" : "");
+			     prefer_ofs_delta ? " ofs-delta" : "",
+			     git_user_agent_sanitized());
 	sent_capabilities = 1;
 }
 
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index d5d7105ba2..7d05064218 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -8,6 +8,7 @@
 #include "send-pack.h"
 #include "quote.h"
 #include "transport.h"
+#include "version.h"
 
 static const char send_pack_usage[] =
 "git send-pack [--all | --mirror] [--dry-run] [--force] [--receive-pack=<git-receive-pack>] [--verbose] [--thin] [<host>:]<directory> [<ref>...]\n"
@@ -251,6 +252,7 @@ int send_pack(struct send_pack_args *args,
 	int status_report = 0;
 	int use_sideband = 0;
 	int quiet_supported = 0;
+	int agent_supported = 0;
 	unsigned cmds_sent = 0;
 	int ret;
 	struct async demux;
@@ -266,6 +268,8 @@ int send_pack(struct send_pack_args *args,
 		use_sideband = 1;
 	if (server_supports("quiet"))
 		quiet_supported = 1;
+	if (server_supports("agent"))
+		agent_supported = 1;
 
 	if (!remote_refs) {
 		fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
@@ -305,12 +309,17 @@ int send_pack(struct send_pack_args *args,
 			char *new_hex = sha1_to_hex(ref->new_sha1);
 			int quiet = quiet_supported && (args->quiet || !args->progress);
 
-			if (!cmds_sent && (status_report || use_sideband || args->quiet)) {
-				packet_buf_write(&req_buf, "%s %s %s%c%s%s%s",
+			if (!cmds_sent && (status_report || use_sideband ||
+					   quiet || agent_supported)) {
+				packet_buf_write(&req_buf,
+						 "%s %s %s%c%s%s%s%s%s",
 						 old_hex, new_hex, ref->name, 0,
 						 status_report ? " report-status" : "",
 						 use_sideband ? " side-band-64k" : "",
-						 quiet ? " quiet" : "");
+						 quiet ? " quiet" : "",
+						 agent_supported ? " agent=" : "",
+						 agent_supported ? git_user_agent_sanitized() : ""
+						);
 			}
 			else
 				packet_buf_write(&req_buf, "%s %s %s",
diff --git a/cache.h b/cache.h
index 67f28b4da9..95daa690aa 100644
--- a/cache.h
+++ b/cache.h
@@ -1038,7 +1038,9 @@ struct extra_have_objects {
 };
 extern struct ref **get_remote_heads(int in, struct ref **list, unsigned int flags, struct extra_have_objects *);
 extern int server_supports(const char *feature);
-extern const char *parse_feature_request(const char *features, const char *feature);
+extern int parse_feature_request(const char *features, const char *feature);
+extern const char *server_feature_value(const char *feature, int *len_ret);
+extern const char *parse_feature_value(const char *feature_list, const char *feature, int *len_ret);
 
 extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
 
diff --git a/connect.c b/connect.c
index 55a85adea9..49e56ba35a 100644
--- a/connect.c
+++ b/connect.c
@@ -115,12 +115,7 @@ struct ref **get_remote_heads(int in, struct ref **list,
 	return list;
 }
 
-int server_supports(const char *feature)
-{
-	return !!parse_feature_request(server_capabilities, feature);
-}
-
-const char *parse_feature_request(const char *feature_list, const char *feature)
+const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 {
 	int len;
 
@@ -132,14 +127,46 @@ const char *parse_feature_request(const char *feature_list, const char *feature)
 		const char *found = strstr(feature_list, feature);
 		if (!found)
 			return NULL;
-		if ((feature_list == found || isspace(found[-1])) &&
-		    (!found[len] || isspace(found[len]) || found[len] == '='))
-			return found;
+		if (feature_list == found || isspace(found[-1])) {
+			const char *value = found + len;
+			/* feature with no value (e.g., "thin-pack") */
+			if (!*value || isspace(*value)) {
+				if (lenp)
+					*lenp = 0;
+				return value;
+			}
+			/* feature with a value (e.g., "agent=git/1.2.3") */
+			else if (*value == '=') {
+				value++;
+				if (lenp)
+					*lenp = strcspn(value, " \t\n");
+				return value;
+			}
+			/*
+			 * otherwise we matched a substring of another feature;
+			 * keep looking
+			 */
+		}
 		feature_list = found + 1;
 	}
 	return NULL;
 }
 
+int parse_feature_request(const char *feature_list, const char *feature)
+{
+	return !!parse_feature_value(feature_list, feature, NULL);
+}
+
+const char *server_feature_value(const char *feature, int *len)
+{
+	return parse_feature_value(server_capabilities, feature, len);
+}
+
+int server_supports(const char *feature)
+{
+	return !!server_feature_value(feature, NULL);
+}
+
 enum protocol {
 	PROTO_LOCAL = 1,
 	PROTO_SSH,
diff --git a/upload-pack.c b/upload-pack.c
index bb08e2eb0d..2e90ccb74f 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -11,6 +11,7 @@
 #include "list-objects.h"
 #include "run-command.h"
 #include "sigchain.h"
+#include "version.h"
 
 static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=<n>] <dir>";
 
@@ -734,9 +735,11 @@ static int send_ref(const char *refname, const unsigned char *sha1, int flag, vo
 	}
 
 	if (capabilities)
-		packet_write(1, "%s %s%c%s%s\n", sha1_to_hex(sha1), refname_nons,
+		packet_write(1, "%s %s%c%s%s agent=%s\n",
+			     sha1_to_hex(sha1), refname_nons,
 			     0, capabilities,
-			     stateless_rpc ? " no-done" : "");
+			     stateless_rpc ? " no-done" : "",
+			     git_user_agent_sanitized());
 	else
 		packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname_nons);
 	capabilities = NULL;
diff --git a/version.c b/version.c
index f98d5a654d..6106a8098c 100644
--- a/version.c
+++ b/version.c
@@ -1,5 +1,6 @@
 #include "git-compat-util.h"
 #include "version.h"
+#include "strbuf.h"
 
 const char git_version_string[] = GIT_VERSION;
 
@@ -15,3 +16,23 @@ const char *git_user_agent(void)
 
 	return agent;
 }
+
+const char *git_user_agent_sanitized(void)
+{
+	static const char *agent = NULL;
+
+	if (!agent) {
+		struct strbuf buf = STRBUF_INIT;
+		int i;
+
+		strbuf_addstr(&buf, git_user_agent());
+		strbuf_trim(&buf);
+		for (i = 0; i < buf.len; i++) {
+			if (buf.buf[i] <= 32 || buf.buf[i] >= 127)
+				buf.buf[i] = '.';
+		}
+		agent = buf.buf;
+	}
+
+	return agent;
+}
diff --git a/version.h b/version.h
index fd9cdd6316..6911a4f155 100644
--- a/version.h
+++ b/version.h
@@ -4,5 +4,6 @@
 extern const char git_version_string[];
 
 const char *git_user_agent(void);
+const char *git_user_agent_sanitized(void);
 
 #endif /* VERSION_H */