From 726569c6bca581a23fd3adb978a726264556efb5 Mon Sep 17 00:00:00 2001
From: Nyall Dawson <nyall.dawson@gmail.com>
Date: Mon, 11 Jul 2016 14:46:08 +1000
Subject: [PATCH] QgsMapLayer::crs() now returns a copy, not a reference

(desirable because QgsCoordinateReferenceSystem is implicitly shared)
---
 doc/api_break.dox           | 6 ++++++
 python/core/qgsmaplayer.sip | 2 +-
 src/core/qgsmaplayer.cpp    | 2 +-
 src/core/qgsmaplayer.h      | 3 +--
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/doc/api_break.dox b/doc/api_break.dox
index 614514e2d71..d87db77b3fe 100644
--- a/doc/api_break.dox
+++ b/doc/api_break.dox
@@ -41,6 +41,12 @@ objects are implicitly shared, returning a copy helps simplify and make code mor
 only affects third party c++ providers, and does not affect PyQGIS scripts.</li>
 </ul>
 
+\subsection qgis_api_break_3_0_QgsMapLayer QgsMapLayer
+
+<ul>
+<li>crs() now returns a QgsCoordinateReferenceSystem object, not a reference. This change has no effect for PyQGIS code.</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsVectorLayerImport QgsVectorLayerImport
 
 <ul>
diff --git a/python/core/qgsmaplayer.sip b/python/core/qgsmaplayer.sip
index dc083cd5e3c..92615d889a8 100644
--- a/python/core/qgsmaplayer.sip
+++ b/python/core/qgsmaplayer.sip
@@ -359,7 +359,7 @@ class QgsMapLayer : QObject
     /** Returns layer's spatial reference system
     @note This was introduced in QGIS 1.4
      */
-    const QgsCoordinateReferenceSystem& crs() const;
+    QgsCoordinateReferenceSystem crs() const;
 
     /** Sets layer's spatial reference system */
     void setCrs( const QgsCoordinateReferenceSystem& srs, bool emitSignal = true );
diff --git a/src/core/qgsmaplayer.cpp b/src/core/qgsmaplayer.cpp
index 22ca275c7eb..4f7618b912c 100644
--- a/src/core/qgsmaplayer.cpp
+++ b/src/core/qgsmaplayer.cpp
@@ -1008,7 +1008,7 @@ void QgsMapLayer::setSubLayerVisibility( const QString& name, bool vis )
   // NOOP
 }
 
-const QgsCoordinateReferenceSystem& QgsMapLayer::crs() const
+QgsCoordinateReferenceSystem QgsMapLayer::crs() const
 {
   return mCRS;
 }
diff --git a/src/core/qgsmaplayer.h b/src/core/qgsmaplayer.h
index dcaf0bbbadd..b10893871af 100644
--- a/src/core/qgsmaplayer.h
+++ b/src/core/qgsmaplayer.h
@@ -378,8 +378,7 @@ class CORE_EXPORT QgsMapLayer : public QObject
     /** Returns layer's spatial reference system
     @note This was introduced in QGIS 1.4
      */
-    //TODO QGIS 3.0 - return QgsCoordinateReferenceSystem object, not reference (since they are implicitly shared)
-    const QgsCoordinateReferenceSystem& crs() const;
+    QgsCoordinateReferenceSystem crs() const;
 
     /** Sets layer's spatial reference system */
     void setCrs( const QgsCoordinateReferenceSystem& srs, bool emitSignal = true );