fix: add poll() compatibility shim for Windows to fix VLC header compilation

src/compat/poll.h

@@ -0,0 +1,90 @@
+// SPDX-FileCopyrightText: 2026 UnionTech Software Technology Co., Ltd.
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef _COMPAT_POLL_H
+#define _COMPAT_POLL_H
+
+#ifdef _WIN32
+
+#include <winsock2.h>
+#include <ws2tcpip.h>
+
+/* struct pollfd is already defined by winsock2.h/ws2def.h as WSAPOLLFD */
+
+#ifndef POLLIN
+#define POLLIN      0x0100
+#endif
+#ifndef POLLOUT
+#define POLLOUT     0x0080
+#endif
+#ifndef POLLERR
+#define POLLERR     0x0001
+#endif
+#ifndef POLLHUP
+#define POLLHUP     0x0002
+#endif
+#ifndef POLLNVAL
+#define POLLNVAL    0x0008
+#endif
+
+static inline int poll(struct pollfd *fds, unsigned int nfds, int timeout) {
+    fd_set r, w, e;
+    FD_ZERO(&r); FD_ZERO(&w); FD_ZERO(&e);
+
+    for (unsigned int i = 0; i < nfds; i++) {
+        fds[i].revents = 0;
+
+        /* Detect invalid sockets before adding to fd_sets */
+        int err = 0;
+        int errlen = sizeof(err);
+        if (getsockopt(fds[i].fd, SOL_SOCKET, SO_ERROR, (char *)&err, &errlen) != 0 || err != 0) {
+            fds[i].revents |= POLLNVAL;
+            continue;
+        }
+
+        if (fds[i].events & POLLIN)  FD_SET(fds[i].fd, &r);
+        if (fds[i].events & POLLOUT) FD_SET(fds[i].fd, &w);
+        FD_SET(fds[i].fd, &e);
+    }
+
+    timeval tv;
+    tv.tv_sec  = timeout / 1000;
+    tv.tv_usec = (timeout % 1000) * 1000;
+
+    int ret = select(0, &r, &w, &e, timeout >= 0 ? &tv : NULL);
+
+    if (ret <= 0) {
+        return ret;
+    }
+
+    for (unsigned int i = 0; i < nfds; i++) {
+        if (fds[i].revents & POLLNVAL)
+            continue;
+
+        if (FD_ISSET(fds[i].fd, &r)) fds[i].revents |= POLLIN;
+        if (FD_ISSET(fds[i].fd, &w)) fds[i].revents |= POLLOUT;
+
+        if (FD_ISSET(fds[i].fd, &e)) {
+            int err = 0;
+            int errlen = sizeof(err);
+            getsockopt(fds[i].fd, SOL_SOCKET, SO_ERROR, (char *)&err, &errlen);
+            if (err == WSAECONNABORTED || err == WSAECONNRESET || err == WSAENOTCONN) {
+                fds[i].revents |= POLLHUP;
+            } else {
+                fds[i].revents |= POLLERR;
+            }
+        } else if (!(fds[i].revents & (POLLIN | POLLOUT)) && (fds[i].events & (POLLIN | POLLOUT))) {
+            /* Socket requested events but none were ready and no error — possible disconnect */
+            char buf;
+            int n = recv(fds[i].fd, &buf, 1, MSG_PEEK);
+            if (n == 0) {
+                fds[i].revents |= POLLHUP;
+            }
+        }
+    }
+    return ret;
+}
+
+#endif /* _WIN32 */
+#endif /* _COMPAT_POLL_H */

src/libdmusic/CMakeLists.txt

@@ -27,8 +27,10 @@ if(VLC_INCLUDE_DIR)
     include_directories(${VLC_INCLUDE_DIR}/vlc)
   endif()
 endif()
-# VLC headers use poll() without including poll.h; force-include it
-add_definitions(-include poll.h)
+# Windows: force-include poll() shim (select-based) so VLC headers compile
+if(WIN32)
+  add_compile_options(-include poll.h)
+endif()
 if(EXISTS "/runtime/include/vlc")
   include_directories(/runtime/include/vlc)
   include_directories(/runtime/include/vlc/plugins)
@@ -56,6 +58,11 @@ qt_add_resources(QRC_FILES ${QRC_SOURCE_FILES})
 
 add_library(${CMD_NAME} SHARED ${ALL_SOURCES} ${QRC_FILES})
 
+# Windows: add compat include directory after target creation
+if(WIN32)
+  target_include_directories(${CMD_NAME} PRIVATE "${CMAKE_SOURCE_DIR}/src/compat")
+endif()
+
 # On MinGW, export all symbols since VLC wrapper classes lack export macros
 if(WIN32 AND NOT MSVC)
     target_link_options(${CMD_NAME} PRIVATE -Wl,--export-all-symbols)
@@ -79,5 +86,10 @@ target_link_libraries(${CMD_NAME} Qt6::Core Qt6::Multimedia Qt6::DBus Qt6::Sql Q
 
 # qt5_use_modules(${CMD_NAME} )
 
+# Windows: always link ws2_32 for Winsock APIs (poll shim, networking)
+if(WIN32)
+    target_link_libraries(${CMD_NAME} ws2_32)
+endif()
+
 include(GNUInstallDirs)
 install(TARGETS ${CMD_NAME} DESTINATION ${CMAKE_INSTALL_LIBDIR})