fix layer mapping in case direct use NOT in a model

Author: luipir

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

@@ -214,6 +214,12 @@ def mappedNameToLayer(self, lyr, expression, layersDict, context):
 
         nameToMap = lyr.source()
 
+        # check if nameToMap is a file
+        # TODO: what about URI eg for a COG?
+        if os.path.isfile(nameToMap):
+            # get only the name without extension and path of the file
+            nameToMap = os.path.splitext(os.path.basename(nameToMap))[0]
+
         # check for layers directly added in the expression
         if (nameToMap + "@") in expression:
             layersDict[nameToMap] = lyr