feat(ha-convergence-recovery): self-restart primitive + demotion convergence (task 2.2)

src/controller/main.c

@@ -109,6 +109,28 @@ static error_t parse_opt(int key, char* arg, struct argp_state* state)
 
 static struct argp argp = { options, parse_opt, args_doc, doc };
 
+/*
+ * Saved argv for self-restart (ha-convergence-recovery Req 1.3).
+ *
+ * main() captures the original, NULL-terminated argv pointer before argp_parse
+ * mutates the program state, so ha_self_restart can execv() the controller back
+ * into existence after a demotion/rejoin convergence truncates the divergent WAL
+ * suffix.  argv supplied to main() is already NULL-terminated per C11 §5.1.2.2.1
+ * (argv[argc] == NULL) and lives for the whole program lifetime, so storing the
+ * pointer is sufficient — no copy needed.
+ */
+static char **g_saved_argv = NULL;
+
+/*
+ * controller_saved_argv — accessor declared in ha.h, consumed by ha_self_restart.
+ * Returns the NULL-terminated argv captured by main(), or NULL if never saved
+ * (e.g. unit-test binaries that do not run main()).
+ */
+char **controller_saved_argv(void)
+{
+    return g_saved_argv;
+}
+
 int main(int argc, char* argv[])
 {
     struct arguments arguments;
@@ -121,6 +143,10 @@ int main(int argc, char* argv[])
     char             cert_file[XCE_MAXPATH_LEN + 1];
     char             myname[XCE_MAXNAME_LEN + 1];
 
+    /* Capture the NULL-terminated argv for self-restart BEFORE argp_parse so a
+     * later demotion/rejoin convergence can execv() the same image (Req 1.3). */
+    g_saved_argv = argv;
+
     memset(&arguments, 0x0, sizeof(arguments));
     arguments.conf_keep_n        = 2;
     arguments.conf_stale_timeout = 86400;