Error when making buffer from empty layer with 'Dissolve result' option checked

[FelisPimeja]

What is the bug or the crash?

When trying to make a buffer from empty layer (produced in processing model for example) with 'Dissolve result' option checked I gain no result and error in the log:

Feature could not be written to Buffered_a03cb901_262a_4ed5_b22c_23aeb10000b1: Could not add feature with geometry type GeometryCollection to layer of type MultiPolygon
Could not write feature into OUTPUT
Execution failed after 0.01 seconds

No error if 'Dissolve result' option stays unchecked.
The problem occurs only with empty layer.

Steps to reproduce the issue

1. Create new empty layer
2. Use Buffer processing algorithm with 'Dissolve result' option checked
3. Get an error

Screen.Recording.2021-12-07.a_t.13.15.16.mov

Versions

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QGIS version	3.22.0-Białowieża	QGIS code revision	d902269
Qt version	5.15.2
Python version	3.9.5
GDAL/OGR version	3.3.2
PROJ version	8.1.1
EPSG Registry database version	v10.028 (2021-07-07)
GEOS version	3.9.1-CAPI-1.14.2
SQLite version	3.35.2
PDAL version	2.3.0
PostgreSQL client version	12.3
SpatiaLite version	5.0.1
QWT version	6.1.6
QScintilla2 version	2.11.5
OS version	macOS 12.0
Active Python plugins
processing	2.12.99
sagaprovider	2.12.99
grassprovider	2.12.99
db_manager	0.1.20
MetaSearch	0.3.5

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

Not OS specific - I get the same behaviour on Windows 10 also.

A workaround with the current behaviour for processing models is to count features in a layer before making a dissolved buffer using Basic statistics for fields algorithm. And check 'Dissolve result' option only when there are more than zero features in the layer.