Fix Linux CI build: C++20 standard, subprocess link, removed APIs

- Remove -std=gnu++11 from Linux target_compile_options so CMAKE_CXX_STANDARD 20 governs (fixes hundreds of CEF 146 C++20 header errors)
- Add libcef.so to cefpython_subprocess link on Linux (fixes undefined cef_* symbol errors)
- Replace removed GdkNativeWindow (GTK2) with unsigned long for gtk_plug_new on Linux
- Remove CefOverridePath calls and declaration (removed from CEF 146 public API)
- Guard CefSetOSModalLoop as Windows-only (was always cef_win.h only)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: linesight

CMakeLists.txt

@@ -223,7 +223,7 @@ elseif(APPLE)
     )
 else()
     target_compile_options(${MODULE_NAME} PRIVATE
-        -std=gnu++11 -DNDEBUG -O3
+        -DNDEBUG -O3
         -flto -fdata-sections -ffunction-sections
     )
     target_compile_definitions(${MODULE_NAME} PRIVATE

src/cefpython.pyx

@@ -452,16 +452,6 @@ def Initialize(applicationSettings=None, commandLineSwitches=None, **kwargs):
     del command_line_switches
     del commandLineSwitches
 
-    IF UNAME_SYSNAME == "Linux":
-        # Fix Issue #231 - Discovery of the "icudtl.dat" file fails on Linux.
-        cdef str py_module_dir = GetModuleDirectory()
-        cdef CefString cef_module_dir
-        PyToCefString(py_module_dir, cef_module_dir)
-        CefOverridePath(PK_DIR_EXE, cef_module_dir)\
-                or Debug("ERROR: CefOverridePath failed")
-        CefOverridePath(PK_DIR_MODULE, cef_module_dir)\
-                or Debug("ERROR: CefOverridePath failed")
-    # END IF UNAME_SYSNAME == "Linux":
 
     if not application_settings:
         application_settings = {}
@@ -983,9 +973,10 @@ def Shutdown():
         MacShutdown()
 
 def SetOsModalLoop(py_bool modalLoop):
-    cdef cpp_bool cefModalLoop = bool(modalLoop)
-    with nogil:
-        CefSetOSModalLoop(cefModalLoop)
+    IF UNAME_SYSNAME == "Windows":
+        cdef cpp_bool cefModalLoop = bool(modalLoop)
+        with nogil:
+            CefSetOSModalLoop(cefModalLoop)
 
 cpdef py_void SetGlobalClientCallback(object name, object callback):
     global g_globalClientCallbacks

src/extern/cef/cef_app.pxd

@@ -30,4 +30,7 @@ cdef extern from "include/cef_app.h":
     cdef void CefDoMessageLoopWork() nogil
     cdef void CefQuitMessageLoop() nogil
     cdef void CefShutdown() nogil
-    cdef void CefSetOSModalLoop(cpp_bool osModalLoop) nogil
+
+IF UNAME_SYSNAME == "Windows":
+    cdef extern from "include/internal/cef_win.h":
+        cdef void CefSetOSModalLoop(cpp_bool osModalLoop) nogil

src/extern/cef/cef_path_util.pxd

@@ -8,4 +8,3 @@ from libcpp cimport bool as cpp_bool
 
 cdef extern from "include/cef_path_util.h" nogil:
     cpp_bool CefGetPath(PathKey key, CefString& path)
-    cpp_bool CefOverridePath(PathKey key, const CefString& path)

src/extern/linux.pxd

@@ -3,9 +3,8 @@
 # Project website: https://github.com/cztomczak/cefpython
 
 cdef extern from "gtk/gtk.h" nogil:
-    ctypedef void* GdkNativeWindow
     ctypedef void* GtkWidget
-    cdef GtkWidget* gtk_plug_new(GdkNativeWindow socket_id)
+    cdef GtkWidget* gtk_plug_new(unsigned long socket_id)
     cdef void gtk_widget_show(GtkWidget* widget)
 
     ctypedef char* XPointer

src/subprocess/CMakeLists.txt

@@ -152,5 +152,6 @@ else()
         CEFPYTHON_API_H_FILE="cefpython_api_fixed.h")
     target_link_libraries(cefpython_subprocess PRIVATE
         "${CEFPYTHON_CEF_ROOT}/lib/libcef_dll_wrapper.a"
+        "${CEFPYTHON_CEF_ROOT}/bin/libcef.so"
     )
 endif()

src/window_utils_linux.pyx

@@ -41,7 +41,7 @@ class WindowUtils:
 
     @classmethod
     def gtk_plug_new(cls, WindowHandle gdkNativeWindow):
-        return <WindowHandle>gtk_plug_new(<GdkNativeWindow>gdkNativeWindow)
+        return <WindowHandle>gtk_plug_new(<unsigned long>gdkNativeWindow)
 
     @classmethod
     def gtk_widget_show(cls, WindowHandle gtkWidgetPtr):