Display (Linux): improve id generation for wayland

Author: CarterLi

src/detection/displayserver/linux/wayland/kde-output.c

@@ -228,7 +228,7 @@ static void waylandKdeOutputOrderListener(void *data, FF_MAYBE_UNUSED struct kde
 {
     uint64_t* id = (uint64_t*) data;
     if (*id == 0)
-        strncpy((char*) id, output_name, sizeof(*id));
+        *id = ffWaylandGenerateIdFromName(output_name);
 }
 
 void ffWaylandHandleKdeOutputOrder(WaylandData* wldata, struct wl_registry* registry, uint32_t name, uint32_t version)

src/detection/displayserver/linux/wayland/wayland.c

@@ -140,7 +140,7 @@ void ffWaylandOutputNameListener(void* data, FF_MAYBE_UNUSED void* output, const
         display->type = FF_DISPLAY_TYPE_EXTERNAL;
     if (!display->edidName.length)
         ffdsMatchDrmConnector(name, &display->edidName);
-    strncpy((char*) &display->id, name, sizeof(display->id));
+    display->id = ffWaylandGenerateIdFromName(name);
     ffStrbufAppendS(&display->name, name);
 }
 

src/detection/displayserver/linux/wayland/wayland.h

@@ -52,6 +52,17 @@ inline static void stubListener(void* data, ...)
     (void) data;
 }
 
+inline static uint64_t ffWaylandGenerateIdFromName(const char* name)
+{
+    uint64_t id = 0;
+    size_t len = strlen(name);
+    if (len > sizeof(id))
+        memcpy(&id, name + (len - sizeof(id)), sizeof(id)); // copy the last 8 bytes
+    else if (len > 0)
+        memcpy(&id, name, len);
+    return id;
+}
+
 void ffWaylandOutputNameListener(void* data, FF_MAYBE_UNUSED void* output, const char *name);
 void ffWaylandOutputDescriptionListener(void* data, FF_MAYBE_UNUSED void* output, const char* description);