Update insets position in cache in more cases

This patch makes sure that, every time a ParagraphMetrics has its
position set, the inset positions for the insets held by this
paragraph are remembered too.

This is complementary to BufferView::updatePosCache, but I do not have
hard evidence that this is required other than to increase robustness.
It may help in some cases when scrolling the document (scrollbar,
cursor up/down, page up/down).

src/BufferView.cpp

@@ -2645,6 +2645,7 @@ bool BufferView::singleParUpdate()
 		// the singlePar optimisation.
 		return false;
 
+	tm.updatePosCache(bottom_pit);
 	d->update_strategy_ = SingleParUpdate;
 
 	LYXERR(Debug::PAINTING, "\ny1: " << pm.position() - pm.ascent()
@@ -2698,6 +2699,7 @@ void BufferView::updateMetrics()
 		}
 	}
 	anchor_pm.setPosition(d->anchor_ypos_);
+	tm.updatePosCache(d->anchor_pit_);
 
 	LYXERR(Debug::PAINTING, "metrics: "
 		<< " anchor pit = " << d->anchor_pit_
@@ -2713,6 +2715,7 @@ void BufferView::updateMetrics()
 		y1 -= pm.descent();
 		// Save the paragraph position in the cache.
 		pm.setPosition(y1);
+		tm.updatePosCache(pit1);
 		y1 -= pm.ascent();
 	}
 
@@ -2726,6 +2729,7 @@ void BufferView::updateMetrics()
 		y2 += pm.ascent();
 		// Save the paragraph position in the cache.
 		pm.setPosition(y2);
+		tm.updatePosCache(pit2);
 		y2 += pm.descent();
 	}
 

src/TextMetrics.cpp

@@ -43,6 +43,7 @@
 
 #include "frontends/FontMetrics.h"
 #include "frontends/Painter.h"
+#include "frontends/NullPainter.h"
 
 #include "support/debug.h"
 #include "support/lassert.h"
@@ -198,6 +199,14 @@ bool TextMetrics::metrics(MetricsInfo & mi, Dimension & dim, int min_width)
 }
 
 
+void TextMetrics::updatePosCache(pit_type pit) const
+{
+	frontend::NullPainter np;
+	PainterInfo pi(bv_, np);
+	drawParagraph(pi, pit, origin_.x_, par_metrics_[pit].position());
+}
+
+
 int TextMetrics::rightMargin(ParagraphMetrics const & pm) const
 {
 	return text_->isMainText() ? pm.rightMargin(*bv_) : 0;
@@ -1214,6 +1223,7 @@ void TextMetrics::newParMetricsDown()
 	redoParagraph(pit);
 	par_metrics_[pit].setPosition(last.second.position()
 		+ last.second.descent() + par_metrics_[pit].ascent());
+	updatePosCache(pit);
 }
 
 
@@ -1228,6 +1238,7 @@ void TextMetrics::newParMetricsUp()
 	redoParagraph(pit);
 	par_metrics_[pit].setPosition(first.second.position()
 		- first.second.ascent() - par_metrics_[pit].descent());
+	updatePosCache(pit);
 }
 
 // y is screen coordinate

src/TextMetrics.h

@@ -62,6 +62,11 @@ public:
 	///
 	void newParMetricsUp();
 
+	/// The "nodraw" drawing stage for one single paragraph: set the
+	/// positions of the insets contained this paragraph in metrics
+	/// cache. Related to BufferView::updatePosCache.
+	void updatePosCache(pit_type pit) const;
+
 	/// Gets the fully instantiated font at a given position in a paragraph
 	/// Basically the same routine as Paragraph::getFont() in Paragraph.cpp.
 	/// The difference is that this one is used for displaying, and thus we