Fix memory access problems in KisExifIo

The problems were caught by KisJpegTest. I have a feeling
there are more problems hidden (all of them are basically
incorrect pointer size iteration).

libs/ui/kisexiv2/kis_exif_io.cpp

@@ -143,6 +143,7 @@ KisMetaData::Value exifOECFToKMDOECFStructure(const Exiv2::Value::AutoPtr value,
     const Exiv2::DataValue* dvalue = dynamic_cast<const Exiv2::DataValue*>(&*value);
     Q_ASSERT(dvalue);
     QByteArray array(dvalue->count(), 0);
+
     dvalue->copy((Exiv2::byte*)array.data());
     int columns = fixEndianess<quint16>((reinterpret_cast<quint16*>(array.data()))[0], order);
     int rows = fixEndianess<quint16>((reinterpret_cast<quint16*>(array.data()))[1], order);
@@ -168,13 +169,14 @@ KisMetaData::Value exifOECFToKMDOECFStructure(const Exiv2::Value::AutoPtr value,
             names.append(KisMetaData::Value(""));
         }
     }
+
     oecfStructure["Names"] = KisMetaData::Value(names, KisMetaData::Value::OrderedArray);
     QList<KisMetaData::Value> values;
-    qint16* dataIt = reinterpret_cast<qint16*>(array.data() + index);
+    qint32* dataIt = reinterpret_cast<qint32*>(array.data() + index);
     for (int i = 0; i < columns; i++) {
         for (int j = 0; j < rows; j++) {
             values.append(KisMetaData::Value(KisMetaData::Rational(fixEndianess<qint32>(dataIt[0], order), fixEndianess<qint32>(dataIt[1], order))));
-            dataIt += 8;
+            dataIt += 2;
         }
     }
     oecfStructure["Values"] = KisMetaData::Value(values, KisMetaData::Value::OrderedArray);
@@ -244,8 +246,10 @@ KisMetaData::Value deviceSettingDescriptionExifToKMD(const Exiv2::Value::AutoPtr
 
     for (int index = 4; index < array.size(); )
     {
-        int lastIndex = array.indexOf(null, index);
-        QString setting = QString::fromUtf16((ushort*)(void*)( array.data() + index), lastIndex - index + 2);
+        const int lastIndex = array.indexOf(null, index);
+        const int numChars = (lastIndex - index) / 2; // including trailing zero
+
+        QString setting = QString::fromUtf16((ushort*)(void*)( array.data() + index), numChars);
         index = lastIndex + 2;
         dbgMetaData << "Setting << " << setting;
         settings.append(KisMetaData::Value(setting));