a5ea9a6fd4
_normalize_main_model_assignment() (POST /api/model/set, the endpoint
Desktop's Settings -> Model page uses to persist the main model slot) has
a fallback for a specific analytics bug: an older session row with no
billing_provider sends the model's bare vendor prefix as "provider"
(e.g. "anthropic" from "anthropic/claude-opus-4.6"), so the code detects
an unrecognized provider paired with a slash-bearing model and treats it
as that stray-vendor-prefix case.
Named custom providers are represented as "custom:<name>" slugs
everywhere else in the codebase (runtime_provider.py, model_switch.py),
but _KNOWN_PROVIDER_NAMES only lists the bare "custom" bucket. So picking
a named custom provider (e.g. "custom:litellm", a LiteLLM proxy fronting
Ollama) together with a slash-bearing model ("ollama/glm-5.2") looked
identical to the stray-vendor-prefix case and got silently rewritten to
provider: openrouter in config.yaml on save -- reassigning the provider
entirely, not just mangling the model id.
Exclude anything starting with "custom" from the fallback, matching the
guard the same function already applies later for the actual
normalize_model_for_provider call.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>