fix: bump protocol version for max alloc wire format

README.md

@@ -466,11 +466,11 @@ defaults to the current directory. |
 
 ## Protocol and Security
 
-FastSync protocol version `2.2.0` is shared by the client and server. The
+FastSync protocol version `2.4.0` is shared by the client and server. The
 current protocol is sender-driven and includes configuration negotiation,
-incremental checks, checksums, manifests, keep-alives, abort handling, and
-FastSync-native delta messages. Client and server versions must currently
-match exactly.
+including the maximum allocation limit, incremental checks, checksums,
+manifests, keep-alives, abort handling, and FastSync-native delta messages.
+Client and server versions must currently match exactly.
 
 TLS provides encrypted TCP transport. Supplying `--ca` enables certificate
 verification; without it, traffic is encrypted but peer identity is not

src/shared/config.h

@@ -129,7 +129,7 @@ typedef struct Config {
   char* compress_choice;
 } Config;
 
-#define PROTOCOL_VERSION "2.3.0"
+#define PROTOCOL_VERSION "2.4.0"
 #define DEFAULT_CHUNK_SIZE (10 * 1024 * 1024)
 
 Config* config_create(void);

tests/test_config.c

@@ -193,7 +193,7 @@ static void test_config_send_receive_version_mismatch() {
   Config* cfg = config_create();
   EXPECT_NOT_NULL(cfg);
   free(cfg->version);
-  cfg->version = str_dup("2.2.0");
+  cfg->version = str_dup("2.3.0");
   cfg->send_directory = str_dup("/src");
   cfg->receive_root_directory = str_dup("/dst");
 
@@ -237,6 +237,8 @@ static void test_config_receive_truncated() {
   /* A valid prefix exercises cleanup after allocated wire strings and a
    * partially received scalar field. */
   EXPECT_TRUE(send_str(p[1], PROTOCOL_VERSION));
+  unsigned long long max_alloc = DEFAULT_MAX_ALLOC;
+  EXPECT_TRUE(send_n_data(p[1], &max_alloc, sizeof(max_alloc)));
   EXPECT_TRUE(send_str(p[1], "/src"));
   EXPECT_TRUE(send_str(p[1], "/dst"));
   EXPECT_TRUE(send_int(p[1], 1));