[NemoIcon] Fixup nemo icon color overlay

src/controls/qml/ApplicationWindow.qml

@@ -196,6 +196,7 @@ NemoWindow {
                     id: mainMenuArea
                     height: parent.height
                     clip: true
+                    visible: width != 0
                     width: if(sourceComponent === null) {
                                return 0
                            } else if (applicationWindow.isUiPortrait) {

src/controls/qml/shaders/NemoIcon.frag

@@ -3,17 +3,18 @@
 layout(location = 0) in vec2 qt_TexCoord0;
 layout(location = 0) out vec4 fragColor;
 
-layout(binding = 1) uniform sampler2D source;
-
 layout(std140, binding = 0) uniform buf {
+    // qt_Matrix and qt_Opacity must always be both present
+    // if the built-in vertex shader is used.
     mat4 qt_Matrix;
     float qt_Opacity;
-
     vec4 color;
-} ubuf;
+};
+
+layout(binding = 1) uniform sampler2D source;
 
 void main()
 {
-    vec4 c = texture(source, qt_TexCoord0);
-    fragColor = c * ubuf.color * ubuf.qt_Opacity;
-}
+    vec4 pixelColor = texture(source, qt_TexCoord0);
+    fragColor = vec4(mix(pixelColor.rgb/max(pixelColor.a, 0.00390625), color.rgb/max(color.a, 0.00390625), color.a) * pixelColor.a, pixelColor.a) * qt_Opacity;
+}