Use QFontMetricsF and ceil() the width() results.

ui/effects/numbers_animation.cpp

@@ -20,7 +20,7 @@ NumbersAnimation::NumbersAnimation(
 , _duration(st::slideWrapDuration)
 , _animationCallback(std::move(animationCallback)) {
 	for (auto ch = '0'; ch != '9'; ++ch) {
-		accumulate_max(_digitWidth, _font->m.horizontalAdvance(ch));
+		accumulate_max(_digitWidth, _font->width(ch));
 	}
 }
 
@@ -76,7 +76,7 @@ void NumbersAnimation::realSetText(QString text, int value) {
 		digit.from = digit.to;
 		digit.fromWidth = digit.toWidth;
 		digit.to = (newSize + i < size) ? QChar(0) : text[newSize + i - size];
-		digit.toWidth = digit.to.unicode() ? _font->m.horizontalAdvance(digit.to) : 0;
+		digit.toWidth = digit.to.unicode() ? _font->width(digit.to) : 0;
 		if (digit.from != digit.to) {
 			animating = true;
 		}
@@ -86,7 +86,7 @@ void NumbersAnimation::realSetText(QString text, int value) {
 	}
 	if (_disabledMonospace) {
 		_fromWidth = _toWidth;
-		_toWidth = _font->m.horizontalAdvance(text);
+		_toWidth = _font->width(text);
 	} else {
 		_fromWidth = oldSize * _digitWidth;
 		_toWidth = newSize * _digitWidth;
@@ -141,10 +141,10 @@ void NumbersAnimation::paint(QPainter &p, int x, int y, int outerWidth) {
 		auto to = digit.to;
 		const auto toCharWidth = (!_disabledMonospace || to.isDigit())
 			? _digitWidth
-			: _font->m.horizontalAdvance(to);
+			: _font->width(to);
 		const auto fromCharWidth = (!_disabledMonospace || from.isDigit())
 			? _digitWidth
-			: _font->m.horizontalAdvance(from);
+			: _font->width(from);
 		if (from == to) {
 			p.setOpacity(1.);
 			singleChar[0] = from;

ui/style/style_core_font.cpp

@@ -17,6 +17,7 @@
 #include <QtGui/QFontInfo>
 #include <QtGui/QFontDatabase>
 #include <QtWidgets/QApplication>
+#include <private/qfontengine_p.h>
 
 void style_InitFontsResource() {
 #ifdef Q_OS_MAC // Use resources from the .app bundle on macOS.
@@ -292,20 +293,26 @@ int registerFontFamily(const QString &family) {
 	return result;
 }
 
+int CeilTextWidth(const QFont &font, const QString &text) {
+	return text.isEmpty()
+		? 0
+		: QStackTextEngine(text, font).width(0, text.size()).ceil().toInt();
+}
+
 FontData::FontData(int size, uint32 flags, int family, Font *other)
 : f(ResolveFont(flags, size))
-, m(f)
+, _m(f)
 , _size(size)
 , _flags(flags)
 , _family(family) {
 	if (other) {
-		memcpy(modified, other, sizeof(modified));
+		memcpy(_modified, other, sizeof(_modified));
 	}
-	modified[_flags] = Font(this);
+	_modified[_flags] = Font(this);
 
-	height = m.height();
-	ascent = m.ascent();
-	descent = m.descent();
+	height = int(base::SafeRound(_m.height()));
+	ascent = int(base::SafeRound(_m.ascent()));
+	descent = int(base::SafeRound(_m.descent()));
 	spacew = width(QLatin1Char(' '));
 	elidew = width("...");
 }
@@ -348,10 +355,10 @@ int FontData::family() const {
 
 Font FontData::otherFlagsFont(uint32 flag, bool set) const {
 	int32 newFlags = set ? (_flags | flag) : (_flags & ~flag);
-	if (!modified[newFlags].v()) {
-		modified[newFlags] = Font(_size, newFlags, _family, modified);
+	if (!_modified[newFlags].v()) {
+		_modified[newFlags] = Font(_size, newFlags, _family, _modified);
 	}
-	return modified[newFlags];
+	return _modified[newFlags];
 }
 
 Font::Font(int size, uint32 flags, const QString &family) {

ui/style/style_core_font.h

@@ -66,46 +66,48 @@ enum FontFlags {
 	FontDifferentFlags = 0x40,
 };
 
+[[nodiscard]] int CeilTextWidth(const QFont &font, const QString &text);
+
 class FontData {
 public:
-	int width(const QString &str) const {
-		return m.horizontalAdvance(str);
+	[[nodiscard]] int width(const QString &text) const {
+		return CeilTextWidth(f, text);
 	}
-	int width(const QString &str, int32 from, int32 to) const {
-		return width(str.mid(from, to));
+	[[nodiscard]] int width(const QString &text, int from, int to) const {
+		return width(text.mid(from, to));
 	}
-	int width(QChar ch) const {
-		return m.horizontalAdvance(ch);
+	[[nodiscard]] int width(QChar ch) const {
+		return int(std::ceil(_m.horizontalAdvance(ch)));
 	}
-	QString elided(
+	[[nodiscard]] QString elided(
 			const QString &str,
 			int width,
 			Qt::TextElideMode mode = Qt::ElideRight) const {
-		return m.elidedText(str, mode, width);
+		return _m.elidedText(str, mode, width);
 	}
 
-	Font bold(bool set = true) const;
-	Font italic(bool set = true) const;
-	Font underline(bool set = true) const;
-	Font strikeout(bool set = true) const;
-	Font semibold(bool set = true) const;
-	Font monospace(bool set = true) const;
+	[[nodiscard]] Font bold(bool set = true) const;
+	[[nodiscard]] Font italic(bool set = true) const;
+	[[nodiscard]] Font underline(bool set = true) const;
+	[[nodiscard]] Font strikeout(bool set = true) const;
+	[[nodiscard]] Font semibold(bool set = true) const;
+	[[nodiscard]] Font monospace(bool set = true) const;
 
 	int size() const;
 	uint32 flags() const;
 	int family() const;
 
 	QFont f;
-	QFontMetrics m;
 	int32 height, ascent, descent, spacew, elidew;
 
 private:
-	mutable Font modified[FontDifferentFlags];
+	mutable Font _modified[FontDifferentFlags];
 
 	Font otherFlagsFont(uint32 flag, bool set) const;
 	FontData(int size, uint32 flags, int family, Font *other);
 
 	friend class Font;
+	QFontMetricsF _m;
 	int _size;
 	uint32 _flags;
 	int _family;

ui/widgets/input_fields.cpp

@@ -3799,7 +3799,7 @@ void InputField::resizeEvent(QResizeEvent *e) {
 }
 
 void InputField::refreshPlaceholder(const QString &text) {
-	const auto availableWidth = width() - _st.textMargins.left() - _st.textMargins.right() - _st.placeholderMargins.left() - _st.placeholderMargins.right() - 1;
+	const auto availableWidth = width() - _st.textMargins.left() - _st.textMargins.right() - _st.placeholderMargins.left() - _st.placeholderMargins.right();
 	if (_st.placeholderScale > 0.) {
 		auto placeholderFont = _st.placeholderFont->f;
 		placeholderFont.setStyleStrategy(QFont::PreferMatch);