push: support push-options

Push options are an optional capability of a git server.  If they are
listed in the servers capabilities, when the client lists push-options
in it's list of capabilities, then the client sends it's list of push
options followed by a flush-pkt.

So, If we have any declared push options, then we will list it as a
client capability, and send the options.

If the request contains push options but the server has no push
options capability, then error.

include/git2/remote.h

@@ -812,6 +812,11 @@ typedef struct {
 	 * Extra headers for this push operation
 	 */
 	git_strarray custom_headers;
+
+	/**
+	 * Push options
+	 */
+	git_strarray push_options;
 } git_push_options;
 
 #define GIT_PUSH_OPTIONS_VERSION 1

include/git2/sys/remote.h

@@ -26,6 +26,9 @@ typedef enum {
 
 	/** Remote supports fetching an individual reachable object. */
 	GIT_REMOTE_CAPABILITY_REACHABLE_OID = (1 << 1),
+
+	/** Remote supports push options. */
+	GIT_REMOTE_CAPABILITY_PUSH_OPTIONS = (1 << 2),
 } git_remote_capability_t;
 
 /**

src/libgit2/push.c

@@ -68,6 +68,14 @@ int git_push_new(git_push **out, git_remote *remote, const git_push_options *opt
 		return -1;
 	}
 
+	if (git_vector_init(&p->push_options, 0, git__strcmp_cb) < 0) {
+		git_vector_free(&p->status);
+		git_vector_free(&p->specs);
+		git_vector_free(&p->updates);
+		git__free(p);
+		return -1;
+	}
+
 	*out = p;
 	return 0;
 }
@@ -472,12 +480,23 @@ static int filter_refs(git_remote *remote)
 int git_push_finish(git_push *push)
 {
 	int error;
+	unsigned int remote_caps;
 
 	if (!git_remote_connected(push->remote)) {
 		git_error_set(GIT_ERROR_NET, "remote is disconnected");
 		return -1;
 	}
 
+	if ((error = git_remote_capabilities(&remote_caps, push->remote)) < 0){
+		git_error_set(GIT_ERROR_INVALID, "remote capabilities not available");
+		return -1;
+	}
+
+	if (git_vector_length(&push->push_options) > 0 && !(remote_caps & GIT_REMOTE_CAPABILITY_PUSH_OPTIONS)) {
+		git_error_set(GIT_ERROR_INVALID, "push-options not supported by remote");
+		return -1;
+	}
+
 	if ((error = filter_refs(push->remote)) < 0 ||
 	    (error = do_push(push)) < 0)
 		return error;
@@ -521,6 +540,7 @@ void git_push_free(git_push *push)
 	push_spec *spec;
 	push_status *status;
 	git_push_update *update;
+	char *option;
 	unsigned int i;
 
 	if (push == NULL)
@@ -543,6 +563,11 @@ void git_push_free(git_push *push)
 	}
 	git_vector_free(&push->updates);
 
+	git_vector_foreach(&push->push_options, i, option) {
+		git__free(option);
+	}
+	git_vector_free(&push->push_options);
+
 	git__free(push);
 }
 

src/libgit2/push.h

@@ -34,6 +34,7 @@ struct git_push {
 	git_vector specs;
 	git_vector updates;
 	bool report_status;
+	git_vector push_options;
 
 	/* report-status */
 	bool unpack_ok;

src/libgit2/remote.c

@@ -2958,6 +2958,13 @@ int git_remote_upload(
 		}
 	}
 
+	if (opts && opts->push_options.count > 0)
+		for (i = 0; i < opts->push_options.count; ++i) {
+			if ((error = git_vector_insert(&push->push_options, git__strdup(opts->push_options.strings[i]))) < 0) {
+				goto cleanup;
+			}
+		}
+
 	if ((error = git_push_finish(push)) < 0)
 		goto cleanup;
 

src/libgit2/transports/smart.c

@@ -233,6 +233,9 @@ static int git_smart__capabilities(unsigned int *capabilities, git_transport *tr
 
 	*capabilities = 0;
 
+	if (t->caps.push_options)
+		*capabilities |= GIT_REMOTE_CAPABILITY_PUSH_OPTIONS;
+
 	if (t->caps.want_tip_sha1)
 		*capabilities |= GIT_REMOTE_CAPABILITY_TIP_OID;
 

src/libgit2/transports/smart.h

@@ -32,6 +32,7 @@
 #define GIT_CAP_SYMREF "symref"
 #define GIT_CAP_WANT_TIP_SHA1 "allow-tip-sha1-in-want"
 #define GIT_CAP_WANT_REACHABLE_SHA1 "allow-reachable-sha1-in-want"
+#define GIT_CAP_PUSH_OPTIONS "push-options"
 
 extern bool git_smart__ofs_delta_enabled;
 
@@ -132,7 +133,8 @@ typedef struct transport_smart_caps {
 	             report_status:1,
 	             thin_pack:1,
 	             want_tip_sha1:1,
-	             want_reachable_sha1:1;
+	             want_reachable_sha1:1,
+	             push_options:1;
 } transport_smart_caps;
 
 typedef int (*packetsize_cb)(size_t received, void *payload);

src/libgit2/transports/smart_protocol.c

@@ -190,6 +190,12 @@ int git_smart__detect_caps(git_pkt_ref *pkt, transport_smart_caps *caps, git_vec
 			continue;
 		}
 
+		if (!git__prefixcmp(ptr, GIT_CAP_PUSH_OPTIONS)) {
+			caps->common = caps->push_options = 1;
+			ptr += strlen(GIT_CAP_PUSH_OPTIONS);
+			continue;
+		}
+
 		if (!git__prefixcmp(ptr, GIT_CAP_THIN_PACK)) {
 			caps->common = caps->thin_pack = 1;
 			ptr += strlen(GIT_CAP_THIN_PACK);
@@ -642,6 +648,7 @@ done:
 static int gen_pktline(git_str *buf, git_push *push)
 {
 	push_spec *spec;
+	char *option;
 	size_t i, len;
 	char old_id[GIT_OID_SHA1_HEXSIZE+1], new_id[GIT_OID_SHA1_HEXSIZE+1];
 
@@ -654,6 +661,8 @@ static int gen_pktline(git_str *buf, git_push *push)
 			++len; /* '\0' */
 			if (push->report_status)
 				len += strlen(GIT_CAP_REPORT_STATUS) + 1;
+			if (git_vector_length(&push->push_options) > 0)
+				len += strlen(GIT_CAP_PUSH_OPTIONS) + 1;
 			len += strlen(GIT_CAP_SIDE_BAND_64K) + 1;
 		}
 
@@ -669,6 +678,10 @@ static int gen_pktline(git_str *buf, git_push *push)
 				git_str_putc(buf, ' ');
 				git_str_printf(buf, GIT_CAP_REPORT_STATUS);
 			}
+			if (git_vector_length(&push->push_options) > 0) {
+				git_str_putc(buf, ' ');
+				git_str_printf(buf, GIT_CAP_PUSH_OPTIONS);
+			}
 			git_str_putc(buf, ' ');
 			git_str_printf(buf, GIT_CAP_SIDE_BAND_64K);
 		}
@@ -676,6 +689,12 @@ static int gen_pktline(git_str *buf, git_push *push)
 		git_str_putc(buf, '\n');
 	}
 
+	if (git_vector_length(&push->push_options) > 0) {
+		git_str_printf(buf, "0000");
+		git_vector_foreach(&push->push_options, i, option) {
+			git_str_printf(buf, "%04"PRIxZ"%s", strlen(option) + 4 , option);
+		}
+	}
 	git_str_puts(buf, "0000");
 	return git_str_oom(buf) ? -1 : 0;
 }