this has been done automatically with the following comand line
./scripts/3to4/3to4.py --only-qgis3-compatible-changes ./python/plugins/
./scripts/3to4/3to4.py --only-qgis3-compatible-changes ./tests/src/python/
When saving a raster expression the generated expression didn't contain square brackets around the letters used for band identifiers. Sticking with the NDVI example:
```
("NIR@1" - "Red@1") / ("NIR@1" + "Red@1")
```
becomes
```
(a - b) / (a + b)
```
Due to the way the expression is parsed these would not be interactie parameters for the user to set as the parameters requre square brackets around the layer tags. This change simply updates the string replacement to include the square brackets so you would get instead:
```
([a] - [b]) / ([a] + [b])
```
Fixes#20601 - bug: Raster calculator produces empty results layer and no error message if input layer is one that has been renamed in QGIS layers panel
- Add abstract base class for Processing widget wrappers to c++
- Add wrapper factory interface to c++
- Make QgsProcessingGuiRegistry also register widget wrapper
factories, and be responsible for creation of new c++
processing widget wrapper instances
- Start on private c++ implementation of boolean widget wrapper,
including unit tests
