Extract the entity parsing code to a static function

This way we can use it from qtdeclarative to parse styled text

Change-Id: Ic888a75a9700558e97b3e743d6d42fda121ddcba
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

src/gui/text/qtexthtmlparser.cpp

@@ -800,28 +800,13 @@ void QTextHtmlParser::parseExclamationTag()
     }
 }
 
-// parses an entity after "&", and returns it
+QString QTextHtmlParser::parseEntity(QStringView entity)
-QString QTextHtmlParser::parseEntity()
 {
-    const int recover = pos;
-    int entityLen = 0;
-    QStringView entity;
-    while (pos < len) {
-        QChar c = txt.at(pos++);
-        if (c.isSpace() || pos - recover > 9) {
-            goto error;
-        }
-        if (c == QLatin1Char(';'))
-            break;
-        ++entityLen;
-    }
-    if (entityLen) {
-        entity = QStringView(txt).mid(recover, entityLen);
     QChar resolved = resolveEntity(entity);
     if (!resolved.isNull())
         return QString(resolved);
 
-        if (entityLen > 1 && entity.at(0) == QLatin1Char('#')) {
+    if (entity.length() > 1 && entity.at(0) == QLatin1Char('#')) {
         entity = entity.mid(1); // removing leading #
 
         int base = 10;
@@ -839,6 +824,29 @@ QString QTextHtmlParser::parseEntity()
             return QStringView{QChar::fromUcs4(uc)}.toString();
         }
     }
+    return {};
+}
+
+// parses an entity after "&", and returns it
+QString QTextHtmlParser::parseEntity()
+{
+    const int recover = pos;
+    int entityLen = 0;
+    while (pos < len) {
+        QChar c = txt.at(pos++);
+        if (c.isSpace() || pos - recover > 9) {
+            goto error;
+        }
+        if (c == QLatin1Char(';'))
+            break;
+        ++entityLen;
+    }
+    if (entityLen) {
+        const QStringView entity = QStringView(txt).mid(recover, entityLen);
+        const QString parsedEntity = parseEntity(entity);
+        if (!parsedEntity.isNull()) {
+            return parsedEntity;
+        }
     }
 error:
     pos = recover;

src/gui/text/qtexthtmlparser_p.h

@@ -310,6 +310,9 @@ public:
     void parse(const QString &text, const QTextDocument *resourceProvider);
 
     static int lookupElement(const QString &element);
+
+    Q_GUI_EXPORT static QString parseEntity(QStringView entity);
+
 protected:
     QTextHtmlParserNode *newNode(int parent);
     QList<QTextHtmlParserNode *> nodes;