Put end label on own row after display inset

This corresponds to what is done on display. The same should be done
for start label too (e.g. beginning of a proof), but this requires more
work.

This required to move the static function getEndLabel to Text.

Fixes bug #11536.

src/RowPainter.cpp

@@ -472,41 +472,9 @@ void RowPainter::paintTopLevelLabel() const
 }
 
 
-/** Check if the current paragraph is the last paragraph in a
-    proof environment */
-static int getEndLabel(pit_type p, Text const & text)
-{
-	ParagraphList const & pars = text.paragraphs();
-	pit_type pit = p;
-	depth_type par_depth = pars[p].getDepth();
-	while (pit != pit_type(pars.size())) {
-		Layout const & layout = pars[pit].layout();
-		int const endlabeltype = layout.endlabeltype;
-
-		if (endlabeltype != END_LABEL_NO_LABEL) {
-			if (p + 1 == pit_type(pars.size()))
-				return endlabeltype;
-
-			depth_type const next_depth =
-				pars[p + 1].getDepth();
-			if (par_depth > next_depth ||
-			    (par_depth == next_depth && layout != pars[p + 1].layout()))
-				return endlabeltype;
-			break;
-		}
-		if (par_depth == 0)
-			break;
-		pit = text.outerHook(pit);
-		if (pit != pit_type(pars.size()))
-			par_depth = pars[pit].getDepth();
-	}
-	return END_LABEL_NO_LABEL;
-}
-
-
 void RowPainter::paintLast() const
 {
-	int const endlabel = getEndLabel(row_.pit(), text_);
+	int const endlabel = text_.getEndLabel(row_.pit());
 	switch (endlabel) {
 	case END_LABEL_BOX:
 	case END_LABEL_FILLED_BOX: {

src/Text.cpp

@@ -288,6 +288,35 @@ Font const Text::outerFont(pit_type par_offset) const
 }
 
 
+int Text::getEndLabel(pit_type p) const
+{
+	pit_type pit = p;
+	depth_type par_depth = pars_[p].getDepth();
+	while (pit != pit_type(pars_.size())) {
+		Layout const & layout = pars_[pit].layout();
+		int const endlabeltype = layout.endlabeltype;
+
+		if (endlabeltype != END_LABEL_NO_LABEL) {
+			if (p + 1 == pit_type(pars_.size()))
+				return endlabeltype;
+
+			depth_type const next_depth =
+				pars_[p + 1].getDepth();
+			if (par_depth > next_depth ||
+			    (par_depth == next_depth && layout != pars_[p + 1].layout()))
+				return endlabeltype;
+			break;
+		}
+		if (par_depth == 0)
+			break;
+		pit = outerHook(pit);
+		if (pit != pit_type(pars_.size()))
+			par_depth = pars_[pit].getDepth();
+	}
+	return END_LABEL_NO_LABEL;
+}
+
+
 static void acceptOrRejectChanges(ParagraphList & pars,
 	BufferParams const & bparams, Text::ChangeOp op)
 {

src/Text.h

@@ -345,6 +345,8 @@ public:
 	/// Get the font of the "environment" of paragraph \p par_offset in \p pars.
 	/// All font changes of the paragraph are relative to this font.
 	Font const outerFont(pit_type pit_offset) const;
+	/// Return the label type at the end of paragraph \c pit.
+	int getEndLabel(pit_type pit) const;
 
 private:
 	/// The InsetText owner shall have access to everything.

src/TextMetrics.cpp

@@ -983,11 +983,17 @@ bool TextMetrics::breakRow(Row & row, int const right_margin) const
 		Inset const * inset = 0;
 		if (par.isNewline(i) || par.isEnvSeparator(i)
 		    || (i + 1 < end && (inset = par.getInset(i + 1))
-			&& inset->display())
+		        && inset->display())
 		    || (!row.empty() && row.back().inset
-			&& row.back().inset->display())) {
+		        && row.back().inset->display())) {
 			row.flushed(true);
-			need_new_row = par.isNewline(i);
+			// We will force a row creation after either
+			// - a newline;
+			// - a display inset followed by a end label.
+			need_new_row =
+				par.isNewline(i)
+				|| (inset->display() && i + 1 == end
+				    && text_->getEndLabel(row.pit()) != END_LABEL_NO_LABEL);
 			++i;
 			break;
 		}