1 files changed, 13 insertions, 14 deletions
diff --git a/src/gui/image/qpnghandler.cpp b/src/gui/image/qpnghandler.cpp
index 7fbd24787e..e9944e1750 100644
--- a/src/gui/image/qpnghandler.cpp
+++ b/src/gui/image/qpnghandler.cpp
@@ -43,13 +43,8 @@
 #include <qvariant.h>
 #include <qvector.h>
 
-#ifdef QT_USE_BUNDLED_LIBPNG
-#include <../../3rdparty/libpng/png.h>
-#include <../../3rdparty/libpng/pngconf.h>
-#else
 #include <png.h>
 #include <pngconf.h>
-#endif
 
 #if PNG_LIBPNG_VER >= 10400 && PNG_LIBPNG_VER <= 10502 \
         && defined(PNG_PEDANTIC_WARNINGS_SUPPORTED)
@@ -108,10 +103,11 @@ public:
     };
 
     QPngHandlerPrivate(QPngHandler *qq)
-        : gamma(0.0), quality(2), png_ptr(0), info_ptr(0), end_info(0), state(Ready), q(qq)
+        : gamma(0.0), fileGamma(0.0), quality(2), png_ptr(0), info_ptr(0), end_info(0), state(Ready), q(qq)
     { }
 
     float gamma;
+    float fileGamma;
     int quality;
     QString description;
     QSize scaledSize;
@@ -234,13 +230,10 @@ void CALLBACK_CALL_TYPE qpiw_flush_fn(png_structp /* png_ptr */)
 }
 
 static
-void setup_qt(QImage& image, png_structp png_ptr, png_infop info_ptr, QSize scaledSize, bool *doScaledRead, float screen_gamma=0.0)
+void setup_qt(QImage& image, png_structp png_ptr, png_infop info_ptr, QSize scaledSize, bool *doScaledRead, float screen_gamma=0.0, float file_gamma=0.0)
 {
-    if (screen_gamma != 0.0 && png_get_valid(png_ptr, info_ptr, PNG_INFO_gAMA)) {
-        double file_gamma;
-        png_get_gAMA(png_ptr, info_ptr, &file_gamma);
-        png_set_gamma(png_ptr, screen_gamma, file_gamma);
-    }
+    if (screen_gamma != 0.0 && file_gamma != 0.0)
+        png_set_gamma(png_ptr, 1.0f / screen_gamma, file_gamma);
 
     png_uint_32 width;
     png_uint_32 height;
@@ -557,6 +550,12 @@ bool Q_INTERNAL_WIN_NO_THROW QPngHandlerPrivate::readPngHeader()
 
     readPngTexts(info_ptr);
 
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_gAMA)) {
+        double file_gamma = 0.0;
+        png_get_gAMA(png_ptr, info_ptr, &file_gamma);
+        fileGamma = file_gamma;
+    }
+
     state = ReadHeader;
     return true;
 }
@@ -580,7 +579,7 @@ bool Q_INTERNAL_WIN_NO_THROW QPngHandlerPrivate::readPngImage(QImage *outImage)
     }
 
     bool doScaledRead = false;
-    setup_qt(*outImage, png_ptr, info_ptr, scaledSize, &doScaledRead, gamma);
+    setup_qt(*outImage, png_ptr, info_ptr, scaledSize, &doScaledRead, gamma, fileGamma);
 
     if (outImage->isNull()) {
         png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
@@ -1063,7 +1062,7 @@ QVariant QPngHandler::option(ImageOption option) const
         return QVariant();
 
     if (option == Gamma)
-        return d->gamma;
+        return d->gamma == 0.0 ? d->fileGamma : d->gamma;
     else if (option == Quality)
         return d->quality;
     else if (option == Description)