Fix `init_x11` return value and X11/XNVCtrl logic checks

src/nvctrl.cpp

@@ -16,14 +16,16 @@ bool nvctrlSuccess = false;
 
 bool checkXNVCtrl()
 {
-    if (init_x11() && nvctrl.IsLoaded()) {
+    if (init_x11()) {
+        if (nvctrl.IsLoaded()) {
             nvctrlSuccess = nvctrl.XNVCTRLIsNvScreen(get_xdisplay(), 0);
             if (!nvctrlSuccess)
                 std::cerr << "MANGOHUD: XNVCtrl didn't find the correct display" << std::endl;
             return nvctrlSuccess;
-    }
+        } else {
-
             std::cerr << "MANGOHUD: XNVCtrl failed to load\n";
+        }
+    }
 
     return false;
 }

src/shared_x11.cpp

@@ -9,13 +9,20 @@ static std::unique_ptr<Display, std::function<void(Display*)>> display;
 
 bool init_x11() {
     static bool failed = false;
-    if (failed || !g_x11->IsLoaded())
+    if (failed)
         return false;
 
     if (display)
         return true;
 
+    if (!g_x11->IsLoaded()) {
+        std::cerr << "MANGOHUD: X11 loader failed to load\n";
+        failed = true;
+        return false;
+    }
+
     const char *displayid = getenv("DISPLAY");
+    if (displayid) {
         auto local_x11 = g_x11;
         display = { g_x11->XOpenDisplay(displayid),
             [local_x11](Display* dpy) {
@@ -23,9 +30,13 @@ bool init_x11() {
                     local_x11->XCloseDisplay(dpy);
             }
         };
+    }
 
     failed = !display;
-    return failed;
+    if (failed)
+        std::cerr << "MANGOHUD: XOpenDisplay failed to open display '" << displayid << "'\n";
+
+    return !!display;
 }
 
 Display* get_xdisplay()