mobile/profile: fix scaling of profile for HDPI screens

For reasons I don't understand, the device pixel ratio was taken into account
twice. And as a result the transformation applied to the profile made us show
only the top left part of it - but enlarged (depending on the DPR).

This code fixes that problem by simply forcing the transformation used by the
painter to be the identity matrix. I worry that this could be wrong in some
situations, but for now it seems to fix the problem.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

CHANGELOG.md

@@ -1,4 +1,5 @@
 - core: avoid crash with corrupted cloud storage
+- mobile: fix profile scaling issue on high DPR devices
 - mobile/Android: add logfiles as attachment to support emails
 - planner: make ESC (cancel plan) work when moving handles
 - dive list: make dive guide visible in dive list [#3382]

profile-widget/qmlprofile.cpp

@@ -51,7 +51,10 @@ void QMLProfile::paint(QPainter *painter)
 		timer.start();
 
 	// let's look at the intended size of the content and scale our scene accordingly
+	// for some odd reason the painter transformation is set up to scale by the dpr - which results
+	// in applying that dpr scaling twice. So we hard-code it here to be the identity matrix
 	QRect painterRect = painter->viewport();
+	painter->resetTransform();
 	if (m_diveId < 0)
 		return;
 	struct dive *d = get_dive_by_uniq_id(m_diveId);