fix prefix path setting: enable running from from build directory

Author: dmarteau

src/server/qgsserver.cpp

@@ -284,13 +284,16 @@ bool QgsServer::init( )
   QCoreApplication::setOrganizationDomain( QgsApplication::QGIS_ORGANIZATION_DOMAIN );
   QCoreApplication::setApplicationName( QgsApplication::QGIS_APPLICATION_NAME );
 
-  //Default prefix path may be altered by environment variable
-  QgsApplication::init();
 #if !defined(Q_OS_WIN)
-  // init QGIS's paths - true means that all path will be inited from prefix
-  QgsApplication::setPrefixPath( CMAKE_INSTALL_PREFIX, true );
+  // Set the QGIS_PREFIX_PATH environnemnt instead of calling directly
+  // setPrefixPath: this will allow running server from build directory
+  // and get the paths accordingly
+  setenv( "QGIS_PREFIX_PATH", CMAKE_INSTALL_PREFIX, 1 );
 #endif
 
+  //Default prefix path may be altered by environment variable
+  QgsApplication::init();
+
 #if defined(SERVER_SKIP_ECW)
   QgsMessageLog::logMessage( "Skipping GDAL ECW drivers in server.", "Server", QgsMessageLog::INFO );
   QgsApplication::skipGdalDriver( "ECW" );