Fix path resolver sometimes returns non empty paths while resolving empty filenames

nyalldawson · nyalldawson · commit cbb683814ff9 · 2018-07-29T09:19:43.000+10:00
(cherry-picked from 3e31a65)
diff --git a/src/core/qgspathresolver.cpp b/src/core/qgspathresolver.cpp
@@ -28,6 +28,9 @@ QgsPathResolver::QgsPathResolver( const QString &baseFileName )
 
 QString QgsPathResolver::readPath( const QString &filename ) const
 {
+  if ( filename.isEmpty() )
+    return QString();
+
   QString src = filename;
 
   if ( mBaseFileName.isNull() )
diff --git a/tests/src/core/testqgsproject.cpp b/tests/src/core/testqgsproject.cpp
@@ -102,6 +102,8 @@ void TestQgsProject::testPathResolver()
 {
   // Test resolver with a non existing file path
   QgsPathResolver resolverLegacy( QStringLiteral( "/home/qgis/test.qgs" ) );
+  QCOMPARE( resolverLegacy.readPath( QString() ), QString() );
+  QCOMPARE( resolverLegacy.writePath( QString() ), QString() );
   QCOMPARE( resolverLegacy.writePath( "/home/qgis/file1.txt" ), QString( "./file1.txt" ) );
   QCOMPARE( resolverLegacy.writePath( "/home/qgis/subdir/file1.txt" ), QString( "./subdir/file1.txt" ) );
   QCOMPARE( resolverLegacy.writePath( "/home/file1.txt" ), QString( "../file1.txt" ) );
@@ -117,6 +119,8 @@ void TestQgsProject::testPathResolver()
   dir.mkpath( tmpDirName + "/home/qgis/" );
 
   QgsPathResolver resolverRel( QString( tmpDirName + "/home/qgis/test.qgs" ) );
+  QCOMPARE( resolverRel.readPath( QString() ), QString() );
+  QCOMPARE( resolverRel.writePath( QString() ), QString() );
   QCOMPARE( resolverRel.writePath( tmpDirName + "/home/qgis/file1.txt" ), QString( "./file1.txt" ) );
   QCOMPARE( resolverRel.writePath( tmpDirName + "/home/qgis/subdir/file1.txt" ), QString( "./subdir/file1.txt" ) );
   QCOMPARE( resolverRel.writePath( tmpDirName + "/home/file1.txt" ), QString( "../file1.txt" ) );

Original file line number	Diff line number	Diff line change
`@@ -28,6 +28,9 @@ QgsPathResolver::QgsPathResolver( const QString &baseFileName )`
`28`	`28`
`29`	`29`	`QString QgsPathResolver::readPath( const QString &filename ) const`
`30`	`30`	`{`
	`31`	`+ if ( filename.isEmpty() )`
	`32`	`+ return QString();`
	`33`	`+`
`31`	`34`	`QString src = filename;`
`32`	`35`
`33`	`36`	`if ( mBaseFileName.isNull() )`