QLocale: simplify currency display name lookup

We were extracting several candidate display names from CLDR for each
currency, joining them with semicolons, storing in a table, then using
only the first entry from the list - where we should probably have
used the first non-empty entry in any case.

So instead extract the first non-empty candidate name from CLDR and
store that simply, saving the need for semicolon-joining or parsing
out the first entry from the thus-joined list. This significantly
reduces the size of the currency name data table.

Change-Id: I201d0528348d5fcb9eceb5df86211b9c77de3485
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

src/corelib/text/qlocale.cpp

@@ -3957,7 +3957,7 @@ QString QLocale::currencySymbol(QLocale::CurrencySymbolFormat format) const
     case CurrencySymbol:
         return d->m_data->currencySymbol().getData(currency_symbol_data);
     case CurrencyDisplayName:
-        return d->m_data->currencyDisplayName().getListEntry(currency_display_name_data, 0);
+        return d->m_data->currencyDisplayName().getData(currency_display_name_data);
     case CurrencyIsoCode: {
         const char *code = d->m_data->m_currency_iso_code;
         if (auto len = qstrnlen(code, 3))

util/locale_database/ldml.py

@@ -265,13 +265,7 @@ class LocaleScanner (object):
         if isoCode:
             stem = 'numbers/currencies/currency[{}]/'.format(isoCode)
             symbol = self.find(stem + 'symbol', '')
-            displays = tuple(self.find(stem + 'displayName' + tail, '')
+            name = self.__currencyDisplayName(stem)
-                for tail in ('',) + tuple(
-                    '[count={}]'.format(x) for x in ('zero', 'one', 'two',
-                                                     'few', 'many', 'other')))
-            while displays and not displays[-1]:
-                displays = displays[:-1]
-            name = ';'.join(displays)
         else:
             symbol = name = ''
         yield 'currencySymbol', symbol
@@ -463,6 +457,18 @@ class LocaleScanner (object):
             sought += ' (for {})'.format(xpath)
         raise Error('No {} in {}'.format(sought, self.name))
 
+    def __currencyDisplayName(self, stem):
+        try:
+            return self.find(stem + 'displayName')
+        except Error:
+            pass
+        for x in  ('zero', 'one', 'two', 'few', 'many', 'other'):
+            try:
+                return self.find(stem + 'displayName[count={}]'.format(x))
+            except Error:
+                pass
+        return ''
+
     def __findUnit(self, keySuffix, quantify, fallback=''):
         # The displayName for a quantified unit in en.xml is kByte
         # (even for unitLength[narrow]) instead of kB (etc.), so