Desktop: Fixed crash when setting spellchecker language to en-IN

packages/app-desktop/services/spellChecker/SpellCheckerServiceDriverNative.ts

@@ -3,6 +3,7 @@
 import SpellCheckerServiceDriverBase from '@joplin/lib/services/spellChecker/SpellCheckerServiceDriverBase';
 import bridge from '../bridge';
 import Logger from '@joplin/lib/Logger';
+import { languageCodeOnly, localesFromLanguageCode } from '@joplin/lib/locale';
 
 const logger = Logger.create('SpellCheckerServiceDriverNative');
 
@@ -18,15 +19,45 @@ export default class SpellCheckerServiceDriverNative extends SpellCheckerService
 
 	// Language can be set to [] to disable spell-checking
 	public setLanguages(v: string[]) {
+
+		// Note that in order to validate the language we need ot set it on the
+		// session and check if Electron has thrown an exception or not. This is
+		// fine because the actual languages will be set below after the calls
+		// to this functions.
+		const validateLanguage = (v: string) => {
+			const languagesToTry = [
+				v,
+				languageCodeOnly(v),
+			].concat(localesFromLanguageCode(languageCodeOnly(v), this.availableLanguages));
+
+			for (const toTry of languagesToTry) {
+				try {
+					this.session().setSpellCheckerLanguages([toTry]);
+					return toTry;
+				} catch (error) {
+					logger.warn(`Failed to set language to "${toTry}". Will try the next one in this list: ${JSON.stringify(languagesToTry)}`);
+					logger.warn('Error was:', error);
+				}
+			}
+
+			return null;
+		};
+
+		const effectiveLanguages: string[] = [];
+		for (const language of v) {
+			const effectiveLanguage = validateLanguage(language);
+			if (effectiveLanguage) effectiveLanguages.push(effectiveLanguage);
+		}
+
 		// If we pass an empty array, it disables spell checking
 		// https://github.com/electron/electron/issues/25228
-		if (v.length === 0) {
+		if (effectiveLanguages.length === 0) {
 			this.session().setSpellCheckerLanguages([]);
 			return;
 		}
 
-		this.session().setSpellCheckerLanguages(v);
+		this.session().setSpellCheckerLanguages(effectiveLanguages);
-		logger.info(`Set effective languages to "${v}"`);
+		logger.info(`Set effective languages to "${effectiveLanguages}"`);
 	}
 
 	public get language(): string {