Fix plurals in translations

See https://github.com/matrix-org/matrix-react-sdk/pull/1358
Requires https://github.com/matrix-org/matrix-react-sdk/pull/1358

scripts/copy-res.js

@@ -156,7 +156,7 @@ function genLangFile(lang, dest) {
     const reactSdkFile = 'node_modules/matrix-react-sdk/src/i18n/strings/' + lang + '.json';
     const riotWebFile = 'src/i18n/strings/' + lang + '.json';
 
-    const translations = {};
+    let translations = {};
     [reactSdkFile, riotWebFile].forEach(function(f) {
         if (fs.existsSync(f)) {
             Object.assign(
@@ -165,6 +165,9 @@ function genLangFile(lang, dest) {
             );
         }
     });
+
+    translations = weblateToCounterpart(translations)
+
     fs.writeFileSync(dest + lang + '.json', JSON.stringify(translations, null, 4));
     if (verbose) {
         console.log("Generated language file: " + lang);
@@ -193,5 +196,39 @@ function genLangList() {
     }
 }
 
+/**
+ * Convert translation key from weblate format
+ * (which only supports a single level) to counterpart
+ * which requires object values for 'count' translations.
+ *
+ * eg.
+ *     "there are %(count)s badgers|one": "a badger",
+ *     "there are %(count)s badgers|other": "%(count)s badgers"
+ *   becomes
+ *     "there are %(count)s badgers": {
+ *         "one": "a badger",
+ *         "other": "%(count)s badgers"
+ *     }
+ */
+function weblateToCounterpart(inTrs) {
+    const outTrs = {};
+
+    for (const key of Object.keys(inTrs)) {
+        const keyParts = key.split('|', 2);
+        if (keyParts.length === 2) {
+            let obj = outTrs[keyParts[0]];
+            if (obj === undefined) {
+                obj = {};
+                outTrs[keyParts[0]] = obj;
+            }
+            obj[keyParts[1]] = inTrs[key];
+        } else {
+            outTrs[key] = inTrs[key];
+        }
+    }
+
+    return outTrs;
+}
+
 genLangList();
 next(0);