From 08f2a02adf6b560b6bd065e4cd95930d45596d83 Mon Sep 17 00:00:00 2001
From: Alessandro Pasotti <elpaso@itopen.it>
Date: Thu, 25 Oct 2018 14:19:31 +0200
Subject: [PATCH 1/2] Ensure save as style file appends qml extension

... or you'll save in the DB instead
---
 src/app/qgisapp.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
index 5fa32b69e39..94b525ec9ca 100644
--- a/src/app/qgisapp.cpp
+++ b/src/app/qgisapp.cpp
@@ -7398,6 +7398,11 @@ void QgisApp::saveStyleFile( QgsMapLayer *layer )
   if ( filename.isEmpty() )
     return;
 
+  if ( ! filename.endsWith( QStringLiteral( ".qml" ) ) )
+  {
+    filename += QStringLiteral( ".qml" );
+  }
+
   bool defaultLoadedFlag;
   layer->saveNamedStyle( filename, defaultLoadedFlag );
 

From 6afb8def0a38b727b552fe6efa9b5eb28807323c Mon Sep 17 00:00:00 2001
From: Alessandro Pasotti <elpaso@itopen.it>
Date: Thu, 25 Oct 2018 14:20:18 +0200
Subject: [PATCH 2/2] Add a test for saveNamedStyle to file path

---
 tests/src/python/test_qgsmaplayer.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tests/src/python/test_qgsmaplayer.py b/tests/src/python/test_qgsmaplayer.py
index 1be12d9a2fa..36dde58b685 100644
--- a/tests/src/python/test_qgsmaplayer.py
+++ b/tests/src/python/test_qgsmaplayer.py
@@ -12,6 +12,7 @@ __copyright__ = 'Copyright 2017, The QGIS Project'
 # This will get replaced with a git SHA1 when you do a git archive
 __revision__ = '$Format:%H$'
 
+import os
 import qgis  # NOQA
 import tempfile
 
@@ -20,6 +21,7 @@ from qgis.core import (QgsReadWriteContext,
                        QgsProject)
 from qgis.testing import start_app, unittest
 from qgis.PyQt.QtXml import QDomDocument
+from qgis.PyQt.QtCore import QTemporaryDir
 
 start_app()
 
@@ -105,6 +107,15 @@ class TestQgsMapLayer(unittest.TestCase):
         self.assertTrue(status)
         self.assertTrue(layer2.metadata().abstract(), 'My abstract')
 
+    def testSaveNamedStyle(self):
+        layer = QgsVectorLayer("Point?field=fldtxt:string", "layer", "memory")
+        dir = QTemporaryDir()
+        dir_path = dir.path()
+        style_path = os.path.join(dir_path, 'my.qml')
+        _, result = layer.saveNamedStyle(style_path)
+        self.assertTrue(result)
+        self.assertTrue(os.path.exists(style_path))
+
 
 if __name__ == '__main__':
     unittest.main()