Filter out patterns without background colors.

Telegram/SourceFiles/boxes/background_preview_box.cpp

@@ -379,15 +379,16 @@ QImage ColorizePattern(QImage image, QColor color) {
 
 QImage PrepareScaledFromFull(
 		const QImage &image,
-		const std::vector<QColor> &patternBackground,
+		bool isPattern,
+		const std::vector<QColor> &background,
 		int gradientRotation,
 		float64 patternOpacity,
 		Images::Option blur = Images::Option(0)) {
 	auto result = PrepareScaledNonPattern(image, blur);
-	if (!patternBackground.empty()) {
+	if (isPattern) {
 		result = Data::PreparePatternImage(
 			std::move(result),
-			patternBackground,
+			background,
 			gradientRotation,
 			patternOpacity);
 	}
@@ -686,7 +687,8 @@ void BackgroundPreviewBox::setScaledFromThumb() {
 	}
 	auto scaled = PrepareScaledFromFull(
 		thumbnail->original(),
-		patternBackgroundColors(),
+		_paper.isPattern(),
+		_paper.backgroundColors(),
 		_paper.gradientRotation(),
 		_paper.patternOpacity(),
 		_paper.document() ? Images::Option::Blurred : Images::Option(0));
@@ -744,12 +746,6 @@ void BackgroundPreviewBox::updateServiceBg(const std::vector<QColor> &bg) {
 		QColor(red / count, green / count, blue / count));
 }
 
-std::vector<QColor> BackgroundPreviewBox::patternBackgroundColors() const {
-	return _paper.isPattern()
-		? _paper.backgroundColors()
-		: std::vector<QColor>();
-}
-
 void BackgroundPreviewBox::checkLoadedDocument() {
 	const auto document = _paper.document();
 	if (!_full.isNull()
@@ -765,17 +761,19 @@ void BackgroundPreviewBox::checkLoadedDocument() {
 		crl::async([
 			this,
 			image = std::move(image),
-			patternBackground = patternBackgroundColors(),
+			isPattern = _paper.isPattern(),
+			background = _paper.backgroundColors(),
 			gradientRotation = _paper.gradientRotation(),
 			patternOpacity = _paper.patternOpacity(),
 			guard = _generating.make_guard()
 		]() mutable {
 			auto scaled = PrepareScaledFromFull(
 				image,
-				patternBackground,
+				isPattern,
+				background,
 				gradientRotation,
 				patternOpacity);
-			auto blurred = patternBackground.empty()
+			auto blurred = !isPattern
 				? PrepareScaledNonPattern(
 					Data::PrepareBlurredBackground(image),
 					Images::Option(0))

Telegram/SourceFiles/boxes/background_preview_box.h

@@ -61,7 +61,6 @@ private:
 	void setScaledFromThumb();
 	void setScaledFromImage(QImage &&image, QImage &&blurred);
 	void updateServiceBg(const std::vector<QColor> &bg);
-	std::vector<QColor> patternBackgroundColors() const;
 	void paintImage(Painter &p);
 	void paintRadial(Painter &p);
 	void paintTexts(Painter &p, crl::time ms);

Telegram/SourceFiles/data/data_wall_paper.cpp

@@ -466,9 +466,6 @@ std::optional<WallPaper> WallPaper::Create(
 			}
 		});
 	}
-	if (result.isPattern() && result.backgroundColors().empty()) {
-		result._backgroundColors.push_back(DefaultBackgroundColor());
-	}
 	return result;
 }
 
@@ -487,9 +484,6 @@ std::optional<WallPaper> WallPaper::Create(const MTPDwallPaperNoFile &data) {
 			}
 		});
 	}
-	if (result.backgroundColors().empty()) {
-		result._backgroundColors.push_back(DefaultBackgroundColor());
-	}
 	return result;
 }
 
@@ -622,9 +616,6 @@ std::optional<WallPaper> WallPaper::FromSerialized(
 	result._backgroundColors = std::move(backgroundColors);
 	result._intensity = intensity;
 	result._rotation = rotation;
-	if (result.isPattern() && result.backgroundColors().empty()) {
-		result._backgroundColors.push_back(DefaultBackgroundColor());
-	}
 	return result;
 }
 
@@ -640,9 +631,6 @@ std::optional<WallPaper> WallPaper::FromLegacySerialized(
 	if (const auto color = ColorFromString(slug)) {
 		result._backgroundColors.push_back(*color);
 	}
-	if (result.isPattern() && result.backgroundColors().empty()) {
-		result._backgroundColors.push_back(DefaultBackgroundColor());
-	}
 	return result;
 }
 
@@ -783,6 +771,9 @@ QImage GenerateDitheredGradient(
 }
 
 QImage GenerateDitheredGradient(const Data::WallPaper &paper) {
+	if (paper.backgroundColors().empty()) {
+		return GenerateDitheredGradient({ DefaultBackgroundColor() }, 0);
+	}
 	return GenerateDitheredGradient(
 		paper.backgroundColors(),
 		paper.gradientRotation());

Telegram/SourceFiles/window/window_main_menu.cpp

@@ -994,7 +994,7 @@ void MainMenu::refreshBackground() {
 		fill,
 		prepared.size());
 
-	auto backgroundImage = !paper.backgroundColors().empty()
+	auto backgroundImage = paper.isPattern()
 		? Data::GenerateWallPaper(
 			fill * cIntRetinaFactor(),
 			paper.backgroundColors(),