get_history_metadata() raises YFPricesMissingError for valid tickers when intraday data is unavailable #2745

Describe bug

get_history_metadata() can raise YFPricesMissingError for valid, non-delisted tickers (e.g., ROG.SW) even after history() succeeds.

The method forces a second request (period="5d", interval="1h") to populate tradingPeriods in the metadata. For some tickers/exchanges, this intraday request returns no price data and raises YFPricesMissingError. The metadata — including currency, exchangeName, timezone, etc. — was already populated by the prior history() call, but the method refuses to return it.

Worse, the failing request can overwrite the already-populated _history_metadata with {} (line 224-225 of history.py), destroying cached metadata.

This is a regression from 0.2.x where get_history_metadata() returned whatever metadata was already cached without the tradingPeriods gate.

Related: #2344 fixed the inverse problem (metadata call corrupting history cache) but introduced this failure path.

Simple code that reproduces your problem

import yfinance as yf
yf.config.debug.hide_exceptions = False

ticker = yf.Ticker("ROG.SW")
df = ticker.history(start="2024-01-01")
print(f"history() OK: {len(df)} rows")

md = ticker.get_history_metadata()  # raises YFPricesMissingError

Root cause

In scrapers/history.py:

def get_history_metadata(self) -> dict:
    if self._history_metadata is None or 'tradingPeriods' not in self._history_metadata:
        self._get_history_cache(period="5d", interval="1h")  # <-- fails here

The or 'tradingPeriods' not in self._history_metadata clause forces a second intraday request even when metadata is already populated. If that request fails, the method raises instead of returning the metadata it already has.

Suggested fix

Two changes:

1. Don't let the tradingPeriods fetch break the getter:

def get_history_metadata(self) -> dict:
    if self._history_metadata is None or 'tradingPeriods' not in self._history_metadata:
        try:
            self._get_history_cache(period="5d", interval="1h")
        except YFPricesMissingError:
            pass  # tradingPeriods is optional enrichment
    ...

2. Don't overwrite good metadata with {} on failure (line ~224):

if data['chart']['result'] is not None:
    self._history_metadata = data["chart"]["result"][0]["meta"]
elif self._history_metadata is None:
    self._history_metadata = {}

yfinance version

Tested on 1.0 and 1.2.1 — both affected.