Nyall Dawson 84c3613cf7 [processing] Don't raise uncaught exceptions when trying to generate
GDAL commands for invalid layers

This is a partial fix, which at least removes the uncaught exception.
Ideally we'd gracefully fall back to using the layer's source
(even if it doesn't exist!) in the generated GDAL commands. But that's
far from trivial to do.

Fixes #51958
2023-02-23 20:48:04 +10:00
..