Fix some warnings and test failures on nightlies

python/plugins/processing/algs/qgis/Merge.py

@@ -84,7 +84,7 @@ class Merge(GeoAlgorithm):
         total = 100.0 / float(totalFeatureCount)
         writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
             fields.toList(), layers[0].dataProvider().geometryType(),
-                layers[0].crs())
+            layers[0].crs())
 
         featureCount = 0
         for layer in layers:

src/app/main.cpp

@@ -307,7 +307,7 @@ void qgisCrash( int signal )
       if ( gdbpid == 0 )
       {
         // attach, backtrace and continue
-        execl( "/usr/bin/gdb", "gdb", "-q", "-batch", "-n", pidstr, "-ex", "thread", "-ex", "bt full", exename, nullptr );
+        execl( "/usr/bin/gdb", "gdb", "-q", "-batch", "-n", pidstr, "-ex", "thread", "-ex", "bt full", exename, NULL );
         perror( "cannot exec gdb" );
         exit( 1 );
       }