Fixed failure to store certain image formats as jpeg

In contrast to other image format handlers, the jpeg handler would not
convert a QImage of an "unusual" format to a format it could handle
when asked to write it. Now it does.

Task-number: QTBUG-7780
Reviewed-by: Trond

1 files changed, 19 insertions, 1 deletions

diff --git a/src/plugins/imageformats/jpeg/qjpeghandler.cpp b/src/plugins/imageformats/jpeg/qjpeghandler.cpp
index 3555b21..6eed824 100644
--- a/src/plugins/imageformats/jpeg/qjpeghandler.cpp
+++ b/src/plugins/imageformats/jpeg/qjpeghandler.cpp
@@ -562,11 +562,29 @@ inline my_jpeg_destination_mgr::my_jpeg_destination_mgr(QIODevice *device)
     free_in_buffer = max_buf;
 }
 
+static bool can_write_format(QImage::Format fmt)
+{
+    switch (fmt) {
+    case QImage::Format_Mono:
+    case QImage::Format_MonoLSB:
+    case QImage::Format_Indexed8:
+    case QImage::Format_RGB888:
+    case QImage::Format_RGB32:
+    case QImage::Format_ARGB32:
+    case QImage::Format_ARGB32_Premultiplied:
+        return true;
+        break;
+    default:
+        break;
+    }
+    return false;
+}
 
 static bool write_jpeg_image(const QImage &sourceImage, QIODevice *device, int sourceQuality)
 {
     bool success = false;
-    const QImage image = sourceImage;
+    const QImage image = can_write_format(sourceImage.format()) ?
+                         sourceImage : sourceImage.convertToFormat(QImage::Format_RGB888);
     const QVector<QRgb> cmap = image.colorTable();
 
     struct jpeg_compress_struct cinfo;