Execute adb start-server

This does nothing if the adb daemon is already started, but allows to
print any output/errors to the console.

Otherwise, the daemon starting would occur during `adb devices`, which
does not output to the console because the result is parsed.

PR #3005 <https://github.com/Genymobile/scrcpy/pull/3005>

app/src/adb/adb.c

@@ -194,6 +194,14 @@ sc_adb_execute(const char *const argv[], unsigned flags) {
     return sc_adb_execute_p(argv, flags, NULL);
 }
 
+bool
+sc_adb_start_server(struct sc_intr *intr, unsigned flags) {
+    const char *const argv[] = SC_ADB_COMMAND("start-server");
+
+    sc_pid pid = sc_adb_execute(argv, flags);
+    return process_check_success_intr(intr, pid, "adb start-server", flags);
+}
+
 bool
 sc_adb_forward(struct sc_intr *intr, const char *serial, uint16_t local_port,
                const char *device_socket_name, unsigned flags) {

app/src/adb/adb.h

@@ -21,6 +21,9 @@ sc_adb_get_executable(void);
 sc_pid
 sc_adb_execute(const char *const argv[], unsigned flags);
 
+bool
+sc_adb_start_server(struct sc_intr *intr, unsigned flags);
+
 bool
 sc_adb_forward(struct sc_intr *intr, const char *serial, uint16_t local_port,
                const char *device_socket_name, unsigned flags);

app/src/server.c

@@ -665,6 +665,15 @@ run_server(void *data) {
 
     const struct sc_server_params *params = &server->params;
 
+    // Execute "adb start-server" before "adb devices" so that daemon starting
+    // output/errors is correctly printed in the console ("adb devices" output
+    // is parsed, so it is not output)
+    bool ok = sc_adb_start_server(&server->intr, 0);
+    if (!ok) {
+        LOGE("Could not start adb daemon");
+        goto error_connection_failed;
+    }
+
     // params->tcpip_dst implies params->tcpip
     assert(!params->tcpip_dst || params->tcpip);
 
@@ -677,7 +686,6 @@ run_server(void *data) {
     // exist, and scrcpy will execute "adb connect").
     bool need_initial_serial = !params->tcpip_dst;
 
-    bool ok;
     if (need_initial_serial) {
         struct sc_adb_device device;
         ok = sc_adb_select_device(&server->intr, params->req_serial, 0,