[libcalamares] Avoid double / between root and path in targetPath()

src/libcalamares/utils/CalamaresUtilsSystem.cpp

@@ -263,6 +263,13 @@ System::runCommand( System::RunLocation location,
     return ProcessResult( r, output );
 }
 
+/// @brief Cheap check if a path is absolute.
+static inline bool
+isAbsolutePath( const QString& path )
+{
+    return path.startsWith( '/' );
+}
+
 QString
 System::targetPath( const QString& path ) const
 {
@@ -277,21 +284,15 @@ System::targetPath( const QString& path ) const
             return QString();
         }
 
-        return gs->value( "rootMountPoint" ).toString() + '/' + path;
+        QString root = gs->value( "rootMountPoint" ).toString();
+        return isAbsolutePath( path ) ? ( root + path ) : ( root + '/' + path );
     }
     else
     {
-        return QStringLiteral( "/" ) + path;
+        return isAbsolutePath( path ) ? path : ( QStringLiteral( "/" ) + path );
     }
 }
 
-/// @brief Cheap check if a path is absolute.
-static inline bool
-isAbsolutePath( const QString& path )
-{
-    return path.startsWith( '/' );
-}
-
 QString
 System::createTargetFile( const QString& path, const QByteArray& contents ) const
 {