Hebrew Locale Corrupts Subsequent Locale Formatting

## Summary Hebrew locale (`'he'`) corrupts Babel's internal cache, causing subsequent `format_date()` calls with other locales to return Hebrew-formatted text instead of the requested locale. ## Environment - **Babel version**: 2.16.0 - **Python version**: 3.12.7 - **Platform**: macOS 26.0.1 (arm64) - **Architecture**: 64bit ## Description When using `babel.dates.format_date()` with Hebrew locale (`'he'`), subsequent calls with other locales (specifically `'no'`, `'fr'`, and others) return Hebrew text instead of the requested locale formatting. This corruption persists throughout the Python session until the process is restarted. ## Steps to Reproduce ### Minimal Reproduction Case ```python from babel.dates import format_date from datetime import datetime # Create a datetime object date_obj = datetime.utcnow() # Test German locale (works correctly) print("German before Hebrew:", format_date(date_obj, 'LLLL', 'de')) # Output: "Oktober" # Use Hebrew locale (works correctly) print("Hebrew:", format_date(date_obj, 'LLLL', 'he')) # Output: "אוקטובר" # Test Norwegian locale (CORRUPTED - returns Hebrew!) print("Norwegian after Hebrew:", format_date(date_obj, 'LLLL', 'no')) # Expected: "oktober" # Actual: "אוקטובר" ❌ # Test French locale (CORRUPTED - returns Hebrew!) print("French after Hebrew:", format_date(date_obj, 'LLLL', 'fr')) # Expected: "octobre" # Actual: "אוקטובר" ❌ # Test German locale (still works correctly) print("German after Hebrew:", format_date(date_obj, 'LLLL', 'de')) # Output: "Oktober" ✅ ``` ### Expected vs Actual Behavior - **Expected**: Each locale should return text in its own language - **Actual**: After Hebrew usage, certain locales return Hebrew text ## Analysis ### Cache Investigation The issue is related to Babel's internal locale data cache (`babel.localedata._cache`): ```python import babel.localedata # Before any locale usage print("Initial cache:", list(babel.localedata._cache.keys())) # Output: [] # After using German format_date(date_obj, 'LLLL', 'de') print("After German:", list(babel.localedata._cache.keys())) # Output: ['root', 'de'] # After using Hebrew format_date(date_obj, 'LLLL', 'he') print("After Hebrew:", list(babel.localedata._cache.keys())) # Output: ['root', 'de', 'he'] # After using Norwegian (corrupted) format_date(date_obj, 'LLLL', 'no') # Returns Hebrew text! print("After Norwegian:", list(babel.localedata._cache.keys())) # Output: ['root', 'de', 'he', 'no'] ``` ### Workaround Clearing the cache after Hebrew usage fixes the corruption: ```python import babel.localedata # Use Hebrew locale format_date(date_obj, 'LLLL', 'he') # Clear cache to prevent corruption babel.localedata._cache.clear() # Now other locales work correctly print(format_date(date_obj, 'LLLL', 'no')) # Returns "oktober" ✅ print(format_date(date_obj, 'LLLL', 'fr')) # Returns "octobre" ✅ ```